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Volume 3 2020


Select key words and find relevant materials scientists or research groups within 4TU.

High-Tech Materials form the key to innovative and sustainable technology @4TU_HTM

4TU.HTM Research Programme New Horizons in Designer Materials | Visibility and accessibility of Materials Science & Engineering | Annual symposium Dutch Materials | 4TU.Joint Materials Science Activities | web application

Innovatieve InnovatieveMaterialen Materialen eenvaktijd­ vak­ About isiseen schrift gericht op de civieltechnische tijdschrift over ontwikkelingen op Innovatieve Materialen het sectorvan en bouw. Het bericht over gebied duurzame, innovatieve (Innovative Materials) is a digital, ontwikkelingen op het gebied van materialen en/of demagazine toepassingabout daarvan independent duurzame, innovatieve materialen en/ in bijzondere constructies.­ material innovation in the fields of of de toepassing daarvan in bijzondere Innovatieve constructies. Materialen werkt nauw engineering, construction (buildings, samen met Stichting MaterialDesign infrastructure and industrial) and

01 News

InnovatieveUitgeverij Materialen is een uitgave van Civiele Techniek, onafhankelijk SJP Uitgevers vaktijdschrift voor civieltechnisch inge­ A digital subscribtion in 2020 nieurs werkzaam in de grond-, weg- en (6 editions) costs € 39,50 Postbus 861 (excl. VAT) waterbouw en verkeerstechniek. Members KIVI and students: 4200of AW Gorinchem € 25,(excl. VAT) tel. (0183) 66 08 08 bijdragen De redactie staat open voor van vakgenoten. U kunt daartoe contact e-mail: opnemen met de redactie.

Ever since the cononavirus has spread around the world, medics, materials techno­ logists, researchers and companies have been working on innovations to help fight the pandemic. This is done with 3D printing technology, among other things. One of the strengths of additive manufacturing (3D printing) is speed, which has proved essential during the current corona pandemic. Moreover, parts or even devices can be produced worldwide via open source networks at lightning speed.

industrial design.

SJP Uitgevers Hoofdredactie: Postbus 861

Gerard Nifterik 4200 AWvan Gorinchem tel. +31 183 66 08 08 Uitgeverij Advertenties

Drs. Petra Schoonebeek SJP Uitgevers e-mail: Publisher Postbus 861 Gerard van Nifterik 4200 abonnement AW Gorinchem Een digitaal in 2020 tel. kost (0183) 66 08(excl. 08 BTW) (6 uitgaven) € 39,50 e-mail:KIVI-leden en studenten: Advertizing € 25,- (excl. BTW)& sponsoring Een papieren abonnement in 2020 Drs. kostPetra € 65,-Schoonebeek (excl. BTW)


Zie ook: Bureau Schoonebeek vof Innovative Materials Hoofdredactie: Niets uit deze uitgave mag worden platform: Gerard Nifterik worden verveelvuldigd en van of openbaar door middel van herdruk, fotokopie, Dr. ir. FredofVeer, prof.wijze ir. Rob microfilm op welke danNijsse ook, (Glass & Transparency Research zonder voorafgaande schriftelijke Advertenties Group, van TU Delft), toestemming de uitgever.

dr. Bert van Haastrecht (M2I), Drs. Petra Schoonebeek prof. Wim Poelman, dr. Ton Innovatieve Materialen Hurkmans (MaterialDesign), e-mail: platform: Jos Brouwers, (Department of BuiltVeer, Environment, Dr.the ir. Fred prof. Ir. RobSection Nijsse Een digitaal abonnement in 2016 Building Physics and Services TU (Glass & Transparency Research Group, (6TUuitgaven) € 25,00 (excl. BTW) Delft), dr.kost Bert van Haastrecht Eindhoven), Jilt Sietsma, (M2I), prof. Mechanical, Wim Poelman,Maritime dr. Ton (4TU.HTM/ Hurkmans (MaterialDesign), and Materials (3mE), Zie Josook: Brouwers, Bouwkunde, Kris Binon(Faculteit (Flam3D), Guido Leerstoel Bouwmaterialen, TU Verhoeven (Bond voor Eindhoven), Jilt Sietsma, Materialenkennis/SIM Flanders, Niets uit deze uitgave mag worden (4TU.HTM/ Werktuigbouwkunde, Prof. dr. ir. Christian Louter verveelvuldigd en of openbaar worden Maritieme Techniek & Technische door middelfür van herdruk, 3mE); fotokopie, Institut Baukonstruktion Materiaalwetenschappen, Kris microfilm of Universität op welkeVerhoeven wijze dan (Bond ook, Technische Dresden). Binon (Flam3D), Guido

10 First wooden wind power tower in Sweden 14 Make it Matter 16 3D printing fights Corona

28 WOW! Turning sewage water into bioplastics

Sewage and industrial wastewater often contain many valuable substances that can be used as raw materials for biobased products. However, this potential is currently not or hardly used, resulting in loss of valuable materials. The INTERREG NWE project WOW! looks into the possibilities to create sustainable value chains from sewage water using these valuable substances. One of the value chains under investigation is the production of PHA (polyhydroxyalkanoates), a fully biodegradable bioplastic.

30 Crystal building: let tiny magnets do the job

Tiny magnetic balls are a popular toy for building great 3D shapes. Imagine you’d want to use this principle for building crystal structures by self-assembly, is a spher­ oid still the best building block? A cuboid, maybe, or a cylinder? Researchers of the University of Twente demonstrate that, in a turbulent water flow, not spheroids but cylinders will form the most regular crystal shape. The work is presented in Science Advances of May 8.

32 A new class of rate-sensitive mechanical metamaterials

Researchers at the Department of Biomechanical Engineering of Delft University of Technology have created a new class of metamaterials that can dynamically switch their mechanical behaviour. It may form the basis for practical applications such as fall-protective clothing for the elderly. The results are to appear in the journal Scien­ ce Advances on 17 June, titled ‘Strain rate-dependent mechanical metamaterials.’

34 Complex soft robotic functions formed in liquid crystal networks

Since their development at the end of last century, reactive mesogens (RM’s) form a versatile class of soft matter materials that have found their way to a wealth of applications. The use of RM’s for soft robotics applications is nowadays studied by many academic and industrial institutes. For instance, at Eindhoven University of Technology, self-sustaining oscillators, cilia based micro-transport devices and haptic surfaces have been developed. In this article we discuss some of our newest deve­ lopments on responsive liquid crystal polymer materials, giving a preliminary view on the future of RM’s with advanced applications in the fields of oscillatory films, smart coatings, soft robotics and haptics.

38 Enterprise Europe Network (EEN)

zonder voorafgaande schriftelijke toe­ voor Materialenkennis/SIM Flanders, stemming van de uitgever. Prof. Dr. ir. Christian Louter Institut für Baukonstruktion Technische Universität Dresden).

Cover: First wooden wind power tower in Sweden; page 10



Perfect acoustic control of the environment Imagine this: you can control the acous­ tics of your environment, no matter the size and shape of the space around you, your access to electricity, and the type of sound you’d like to control. That is what the ADAM project prototype offers. ADAM stands for Acoustics by parame­ tric Design and Additive. With the use of mathematical models and 3D printing, amongst others, ADAM allows the creati­ on of tailor made sound absorbers, such as tubes integrated in a 3D printed geo­ metry like a curved panel or freestanding form. The sound absorbers of the proto­ type make us of the principle of Passive Destructive Interference (PDI). According to PDI, interfering sound waves that are in counter-phase are self-cancelled. To achieve this self-cancellation, series of tubes in varying lengths and diameters


are used. As a result, the acoustic perfor­ mance of ADAM is strongly related to its predefined geometrical characteristics, and can be easily customised to meet specific requirements. The research project is the first to explore passive destructive interference sound absorbers in combination with additive manufacturing in a high level of detail. The multidisciplinary research team from the faculty of Architecture and the Built Environment connects the fields of Environmental Technology & Design, Building Physics & Services, and Design Informatics. The additional collaboration with industry partners created the vital knowledge exchange to develop the new techniques. Amongst others, acoustic

consultancy firm Peutz opened up their testing facilities, and Belgian company Materialise helped develop the novel 3D printing techniques. Much more at the TU Delft> For more info please contact: Arjan van Timmeren Martin Tenpierik Michela Turrin



New, super-fast method for ceramic manufacturing Ceramics are widely used in batteries, electronics, and extreme environments. Conventional ceramic sintering (part of the firing process used in the manufac­ ture of ceramic objects) often requires hours of processing time. To overcome this challenge, Scientists in the Univer­ sity of Maryland (UMD)’s A. James Clark School of Engineering have developed an ultrafast high-temperature sintering method. Last May, the results of this study were published in Science. Conventional sintering techniques requi­ re a long processing time - it takes hours for a furnace to heat up, then several hours more to ‘bake’ the ceramic mate­ rial. Alternative sintering technologies (such as microwave-assisted sintering, spark plasma sintering, and flash sinte­ ring) are limited for a variety of reasons, often because they are material-specific and/or expensive. The Maryland team’s new method of ultrafast high-temperature sintering of­ fers high heating and high cooling rates, an even temperature distribution, and sintering temperatures of up to 3,000 °C. Combined, these processes require less than 10 seconds of total processing time - according to UMD more than 1,000 times faster than the traditional furnace approach of sintering. The trick is to ‘sandwich’ a pressed green pellet of ceramic precursor powders between two strips of carbon that quic­ kly heated the pellet through radiation and conduction, creating a consistent high-temperature environment that forced the ceramic powder to solidify quickly. According the research team, the temperature is high enough to sinter basically any ceramic material. The patented, rapid sintering technology is being commercialized through HighTTech LLC, a UMD spinoff company with a focus on a range of high temperature technologies ( The study, led by Liangbing Hu, Herbert

Rabin Distinguished Professor of the Department of Materials Science and Engineering and director of the Center for Materials Innovation at UMD, was published on the May 1 in Science, titled

‘A general method to synthesize and sinter bulk ceramics in seconds’ (DOI: 10.1126/science.aaz7681). More at UMD>



Grass2Grit: de-icing roads with grass

The province of North Holland is going to use a new grass thawing agent to combat slippery conditions on the N504 north of Alkmaar. According to the province, the (partial) replacement of salt by grass juice and the processing of the fibers (Grass2Grit) is a circular and innovative application. Grass2Grit is a circular concept in which roadside grass is processed into grass juice and grass fibres. The juice is used for de-icing roads and the fibres are used for road furniture. Grass2Grit’s idea was born when Hillebrand Breuker of the province of Noord-Holland was working with grass fibres and one day noticed that the juice that was obtained from pressing was quite salty. Research was conducted and a first Life Cycle Ana­ lysis (LCA) of the Grass2Grit technique was completed in 2017. The conclusion: there is a lot of potential. In addition to demonstrating this circular approach, the project will lead to a num­ ber of positive environmental effects. By mowing more often in an environmen­ tally friendly way and clearing the grass, the biodiversity along the road will increase. In addition, the pollution of verges will decrease because of the use of biobased road furniture.


Opened in early March, the Grass2Grit factory will use the ‘roadside juice’ as an alternative road salt on the N504 until the end of 2022. It is expected that bet­ ween 6 and 10 tons of fresh grass will be

needed. The grass fibers released during the production of the juice can be used for making biobased road furniture. The Grass2Grit project is the first concept in the world to use roadside grass to com­

NEWS bat slippery conditions on roads along which the roadside grass grows. The project received a LIFE grant1 in 2018 in the category ‘environment and resource efficiency’, with which a pilot can be carried out. Grass2Grit is a joint ventu­ re of the province of North Holland, J. van Bodegom & Zn, Van Gelder, Natural Plastics and Schuitemaker. If the pilot project on the N504 is suc­ cessful, Grass2Grit expects to expand nationally and internationally. Provincie Noord-Holland (Dutch)> Grass2Grit website> LIFE is a subsidy program, supporting innovative projects that fit into European nature, environment and climate policy.





Expandable foam for 3D printing large objects It’s a frustrating limitation of 3D printing: printed objects must be smaller than the machine making them. Huge machines are impractical for printing large parts because they take up too much space and require excessive time to print. Now, a new material reported in ACS Applied Materials & Interfaces can be used to 3D print small objects that expand upon heating. The foam could find applications in architecture, aerospace and biomedicine. One type of 3D printing, stereolithography, creates objects by exposing sequential layers of light-sensitive resins to patterns of light, which cure the polymer into the desired shape. Large objects can be created with specialized stereolithography ma­ chines, but they are usually made by fastening smaller 3D-prin­ ted components together. David Wirth, Jonathan Pokorski and colleagues at the University of California, San Diego wanted to develop an expandable resin that could be used to print large objects with an inexpensive, commercially available 3D printer. The researchers tested many different resin formulations to find one that allowed them to print an object that, when exposed to heat, expanded to a larger size. They used the formulation to 3D print a hollow, latticed sphere. Heating the sphere in an oven caused a volatile component of the resin to bubble out as a gas. This created a porous, polystyrene foam-li­ ke material that was up to 40 times larger in volume than the original printed object. With this method, the team also 3D printed many other shapes, including a boat, which could carry about 20 times more weight at its expanded size, and a wind turbine that could produce a small amount of electricity at its larger size. Although the new material isn’t as strong as poly­ styrene foam, it could someday be used for cushioning, airfoils, buoyancy aids or even expandable habitats for astronauts, the researchers say. Credits: ACS> The article ‘Highly Expandable Foam for Lithographic 3D Printing’ was published in ACS Applied Materials & Interfaces and can be found here>




‘The most heat-resistant material ever’ Scientists from the Russian NUST MISIS (National University of Science & Tech­ nology, Moscow) developed a ceramic material with the highest melting point among currently known compounds. Due to the unique combination of physi­ cal, mechanical and thermal properties, the material is promising for use in the most heat-loaded components of aircraft- and aerospace, such as nose fairings, jet engines and sharp front ed­ ges of wings operating at temperatures above 2000 °C. The results are published in Ceramics International. The goal of the scientists was to create a material with the highest melting point and high mechanical properties. The

triple hafnium-carbon-nitrogen system, hafnium carbonitride, was chosen, since previously scientists from Brown University (USA) predicted that hafnium carbonitride would have a high thermal conductivity and resistance to oxidati­ on, as well as the highest melting point among all known compounds (approxi­ mately 4200 °C). Using the method of self-propagating high-temperature synthesis, NUST MISIS scientists managed to obtain a material HfC0.5 N0.35, (hafnium carbonitride) close to the theoretical composition, with a high hardness of 21.3 GPa, which is even higher than in new promising materials, such as ZrB2/SiC (20.9 GPa)

and HfB2/SiC/TaSi2 (18.1 GPa). However, at the moment the specific melting point of the new material is abo­ ve 4000 °C, and could not be determined precisely in the laboratory. In the future, the team plans to conduct experiments on measuring the melting temperature by high-temperature pyrometry using a laser or electric resistance. It is also planned to study the performance of the resulting hafnium carbonitride in hyper­ sonic conditions, which will be relevant for further application in the aerospace industry. More at NUST MISIS>



Lignin replaces phenol For the first time, panels for high-qua­ lity applications in interiors have been launched in which 50 % phenol has been replaced by the natural adhesive lignin. This is the result of eight-year long part­ nership by Wageningen Food & Biobased Research and NEMHO, the R&D depart­ ment for Dutch producer Trespa Inter­ national B.V, Italian sister company Arpa Industriale and other material techno­ logy companies of Broadview Holding. Arpa HPL and FENIX NTM panels are made of paper and thermosetting resins based on phenol. Thermal pressure creates a durable structure that makes the material suitable for interior appli­ cations. For years, phenol has been used in these thermosetting resins. However, the substance is on the EU list of sub­ stances of very high concern. NEMHO and Wageningen Food & Biobased Research work together to develop an alternative resin based on lignin tech­


Arpa Fenix Interzum

NEWS nology. The natural adhesive lignin is found in woody crops and is abundant in nature. In the new production process, optimal use is made of the intrinsic binding properties of lignin. To guarantee the supply of sufficient lignin, the choice was made for lignin that is released as a side stream that is released during the Kraft process, the most important pulp process to produce cellulose for paper. In this process, wood is processed into wood pulp. It was investigated how the lignin behaves in the synthesis of the lignin-based resin and gluing process. It showed that lignin needs to be modified before it can be used. After eight years of research by NEMHO and Wageningen Food & Biobased Research, this resulted in a breakthrough in which 50 percent phenol could be replaced by lignin.

NEMHO also collaborated with VTT (Technical Research Centre of Finland), the Helsinki University and UPM Oy to come to a commercially viable product. The ambition is now to be able to, even­ tually, completely replace phenol with lignin in the thermosetting resin. A call has now been made for a new research program to increase the replacement rate step by step. It is expected the industry will join: phenol is a substance that the industry wants to get rid of as soon as possible. WUR>

HĂŠt expertisecentrum voor materiaalkarakterisering. Integer, onafhankelijk, objectief onderzoek en advies. ISO 17025 geaccrediteerd. Wij helpen u graag verder met onderzoek en analyse van uw innovatieve materialen. Bel ons op 026 3845600 of mail



First wooden wind power tower in Sweden At the end of April, Sweden’s first wooden wind turbine is now ready on Björkö outside Gothenburg. The tower is 30 meters high and was erected by the development company Modvion. Go­ thenburg company Modvion specializes in developing complex designs for large laminated timber structures. Such wood constructions are interesting because,




according to the company, they are as strong as steel and are therefore a good alternative to emission-intensive mate­ rials such as steel and concrete. Carbon dioxide absorbed by trees is stored in the wooden towers, making the wind turbines climate neutral from the start. According to Modvion, wind towers of wood can be built cheaper than of steel, which logically also reduces the costs of wind energy. The lower weight of the wood and the modular concept also make it possible to build higher towers. The sections can be easily transported by public road.

already in 2022, the first wooden towers will be built on a commercial scale. Modvion has signed declarations of in­ tent with Varberg Energi for a 110 meter high tower and with Rabbalshede Kraft for 10 towers, at least 150 meters high. Moelven Töreboda AB>

The 30-meter-high tower was built in cooperation with Moelven at the wood factory in Töreboda. The intention is to continue production in collaboration with Moelven Töreboda AB in the future. The activities are funded by the Swedish Energy Agency, the Västra Götaland Regi­ on and the EU programme Horizon 2020 SME Instruments Phase 1. The Swedish Wind Power Technology Centre at Chal­ mers is the client for the wooden tower on Björkö. The new wind energy tower will be used for research purposes. But



Augmented reality bricklaying Last May, MaterialDistrict payed attenti­ on to the The Kitrvs winery façade pro­ ject by Gramazio Kohler Research, ETH Zurich. The 225 m2 large wavy façade was built to demonstrate how augmen­


ted bricklaying combines the advantages of computational design with the dex­ terity of humans, supporting an entirely new way of fabrication. The Kitrvs winery façade is built of 13596

handmade bricks. According to ETHZ It is currently the largest project entirely assembled on-site with an interactive design system and augmented reality interface. Using a custom made dynamic

NEWS optical guidance system developed by researchers of ETH Zürich, local masons constructed the façade in less than three months. Earlier, in 2006, the project ‘Weingut Gantenbein’ by Gramazio Kohler Rese­ arch proves that robotic systems are very suitable to achieve intricate brickwork designs with high efficiency. Neverthe­ less, standard robotic arms come with limitations, such as limited mobility and dexterity, or the handling of certain building materials such as mortar. This is why Gramazio Kohler Research reintro­ duced the craftsmen back in the digital fabrication process. By optically instruc­ ting masons via digital pointers, a direct connection to a digital design model is made. Following such digital instruc­ tions, the masons no longer depend on physical templates. In addition, this process enables masons to work with enhanced spatial precision, while preser­

ving and capitalizing on their craft and expertise in mortar handling. The result is a wavy, semi-transparent parametric façade, which ‘reflects the idea of an ever-changing façade pat­ tern resembling the shimmering light of liquid.’ Gaps between the individual bricks allow for ventilation and to control sunlight. More at Gramazio Kohler Research, ETH Zurich>

Credits: Gramazio Kohler Research, ETH Zürich Client: KITRVS Winery In cooperation with: dr. Kathrin Doerfler (project lead), Daniela Mitterberger, dr. Timothy Sandy, Foteini Salveridou, Fernando Cena, Lukas Stadlmann, Lefteris Kotsonis, Eleni Alexi, Dimitris Ntantamis Consultancy: Dr. Nebojsa Mojsilovic, Structural Masonry, ETH Zurich Selected experts: Dr. Tobias Bonwetsch, ROB Technologies AR-Tracking-System von


Photography: Michael Lyrenmann/Gra­ mazio Kohler Research, ETHZ



MAKE IT MATTER MAKE IT MATTER is compiled in collaboration with MaterialDistrict ( In this section new, and/or interesting developments and innovative materials are highlighted.

Terra collection The Terra collection brings together a group of objects made from 100 % recycled terrazzo and marble aggregates, and Green label cement. The structure of the pieces consists of simple shapes that emphasize the natural texture of the ce­ ment and the various recycled aggregates. Following the circu­ lar economy, the pieces are made of concrete with embedded marble chips, hydraulic tiles and terrazzo, giving them a new life. Each piece can be personalized according to the client’s preferences (colours, aggregates shapes, textures and sizes.

More at MaterialDistrict>

PET Felt Acoustic Panels PET Felt Acoustic Panels are large sturdy sheets, that are soft to touch. The panels are made from PET Felt, recycled plastic bottles. Suitable for various applications, including wall and ceiling covering, room dividers or custom installations. Availa­ ble in 28 colour blends. The acoustic performance is due to its open-cellular structure. PET Felt Panels are durable, can be processed in various ways and recycled after the long-time use. More at MaterialDistrict>

Laminated linoleum Laminated linoleum is a new material, consisting of laminated furniture linoleum layers. Laminating this material creates a sturdy plate that can be used for various purposes, such as ma­ king table tops and chair seats. It’s scratch and water resistant. And completely made out of leftovers. There is no ‘new’ mate­ rial added besides wood glue.

More at MaterialDistrict>


MAKE IT MATTER Pavilion made of recycled plastic Hong Kong-based architectural firm Daydreamers Design cre­ ated a pavilion made of recycled plastic bricks, inspired by the traditional local custom of the burning tower and sky lanterns in the Mid-Autumn Festival. The installation is made of 5000 bricks representing the 5000 years of Chinese civilisation. The bricks are made of recycled high-density polyethylene (HDPE) and have seven gradient colours from yellow to red.

More at MaterialDistrict>

London Unglazed London Unglazed is an unglazed resistant and durable porce­ lain mosaic in hexagon shape. This full body mosaic range is very suitable for the floor. London Unglazed is available in two tile sizes: 23 x 26 x 5 mm and 51 x 59 x 6 mm.

More at MaterialDistrict>

3D printed recycled plastic The New Raw transforms plastic waste into street furniture and building components with robotic 3D printing and parti­ cipatory design. This zero-waste approach optimises the recy­ cling process of plastic by introducing new digital and design technologies in the recycling process of discarded materials. The New Raw is a Research & Design studio based in Rotter­ dam (The Netherlands), founded in 2015. More at MaterialDistrict>

Fraké Noir Fraké noir is a fully modified, walnut-like hardwood and suitable for several applications, but mainly used for façade cladding. The hardwood is sourced from Africa from sustaina­ ble managed forests and the pattern, black lines and pinholes makes it known as African-Oak. By thermal treatment Fraké Noir is graded with durability class 1 and therefore perfectly suitable for outdoor applications. Fraké Noir is impact resistant and dimensionally stable, making it both practical and versati­ le. More at MaterialDistrict>



The 3D printed Venturi valves by the Italian 3D printing startup Issinova (image: Cristian Fracassi/Issinova)

3D printing fights Corona Ever since the cononavirus has spread around the world, medics, materials technologists, researchers and companies have been working on innovations to help fight the pandemic. This is done with 3D printing technology, among other things. One of the strengths of ad­ ditive manufacturing (3D printing) is speed, which has proved essential during the current corona pandemic. Moreover, parts or even devices can be produced worldwide via open source networks at lightning speed.

Early March, as the coronavirus began to spread in Italy, a hospital in the town of Chiari lacked an essential ventilator part called a ‘venturi valve,’ the component required to connect an oxygen mask to a respirator. Cristian Fracassi, CEO of the 3D-printing start up Issinova, and his team answered the call by 3D printing 100 life-saving respirator valves in 24 hours. It is one example of how makers of 3D-printing technologies are using their systems to quickly create life-saving parts and prototypes like masks, shields, ventilator valves and other devices.

Face shield

In the United States, Stratasys crea­ ted 5,000 face shields by March 27.


‘Avete salvato delle vite’, You saved lives. Giornale di Brescia, March 17 2020

INNOVATIVE MATERIALS 3 2020 Early April, Materialise presented a self-developed, 3D Printed Oxygen PEEP Mask. (PEEP stand for apply Positive End Expiratory Pressure.) Around the world, hospitals are looking for medical equipment capable of de­ livering air with added oxygen to treat critically ill coronavirus patients. Current­ ly this treatment is carried out using me­ chanical ventilators, which are critically under-supplied. As a result, clinicians today are exploring different methods to apply positive end expiratory pressure (PEEP) to the lungs of COVID 19 patients without the use of a ventilator. Materia­ lise has developed a solution to deliver oxygen and create high positive pressure without the use of a ventilator. This 3D printed connector, converts standard equipment already available in most hospitals into a non-invasive PEEP

3D printed face shield frames (Photo: Stratasys)

Stratasys, Ltd. is an American manufac­ turer of 3D printers and 3D production systems for office-based rapid prototy­ ping and direct digital manufacturing. The face shield has a 3D printed frame and transparent plastic shield to provi­ de protection to healthcare workers, it will be provided at no cost to medical personnel.

healthcare workers, to making remote working and learning easier. Materialise, headquartered in Belgium, was established in 1990. The company has branches worldwide, and claims to combine the largest group of software developers in the industry with one of the largest 3D printing facilities in the world.


Open source

In Spain Barcelona-based BCN3D has offered up its own in-house print farm of 63 machines to combat the medical device shortage around the world. Many initiatives followed, bringing to­ gether engineers through open source. With teams all around the world looking to help hospitals and patients in need, open-source designs have led to a spirit of collaboration among engineers and manufacturers. 3D printing technology does the remaining part. For instance the Open Source Ventilator Project, where with the help of engi­ neers around the world a working ven­ tilator can be built with 3D printers and ready-made, 3D printed components. (More at Nasa Techbriefs>)


The Belgian company Materialise has been working on several fronts to respond to the corona pandemic, from developing certified medical devices to help patients, to protective devices for

3D Printed Oxygen PEEP Mask (Photo: Materialise)


INNOVATIVE MATERIALS 3 2020 mask (NIP). It can be connected to the oxygen supply to facili­ tate breathing for coronavirus patients. ‘3D printing is playing a crucial role in fighting the global co­ ronavirus pandemic by making it possible to develop innova­ tive solutions and have them available worldwide very quickly,’ said Brigitte De Vet, Vice President of Materialise Medical, at the presentation of the device. More at Materialise> In addition to the NIP solution, Materialise developed several innovations to support treatment and containment of the coronavirus, including a 3D printed shopping cart handle to allow users to steer carts with their arms rather than touching handles with bare hands. Furthermore the company develo­ ped a 3D printed door handle attachment, which allows users to open doors using covered forearms rather than bare hands in an effort to reduce direct contact with potentially contami­ nated shared door handles. The 3D printed door opener can be attached to existing door handles without drilling holes or replacing the handle. It fea­ tures a paddle-shaped extension, allowing people to open and close doors while using their arm instead of their hands, as

3D printed door handle attachment; Materialise

tive pressure in the mask, potentially reducing air leakage and promoting the ease of breathing. Preliminary testing indicates that the solution provides better protection than the com­ monly used FFP2 masks. The COVID Lifesaver Mask, which was developed at the same time, does not yet meet the required safety standards in a clinical setting. More at TUD>

3D printable respirator Video

most doors can’t remain open due to safety reasons. Door handles are among the most germ-infested objects in houses, hospitals, factories, and elderly homes. Soon after cre­ ating the door opener, Materialise realized that more people could benefit from the protective measure and the company decided to make the design available for free. Henceforth, anyone with a 3D printer can download the file and produce the door opener locally, making the 3D printed door opener available all over the world, citing the fact that over 500,000 3D printers were sold globally in 2018.

The Czech Institute of Informatics, Robotics and Cybernetics at the Czech Technical University in Prague (CIIRU CTU) has deve­ loped a new 3D printable respirator called the CIIRC RP95. According to the institute, the CIIRC RP95-3D is a personal pro­ tective equipment - half-mask - with a P3 replacable external

Reusable face masks

In the Netherlands two new reusable face masks for medical staff who are caring for and treating corona patients have been developed by teams of anaesthesiologists, universities and a consortium of companies, all supporting on a non-profit basis. Both masks use a 3D printed connector to link a popular snor­ kel mask to a filter system. The COVID Lifesaver Mask uses a high-performance filter used in anaesthetic equipment to cre­ ate a low-cost, easy to use system for short duration use. The Air-Wave Protector solution uses an industrial fan & filter unit to create a personal protection unit for use of longer duration. The Air-Wave Protector is a combination of a full face snor­ kel mask connected with a custom 3D printed connector to a medical-grade filter and an air pump used in the welding industry for personal protection. The air pump creates a posi­


COVID Lifesaver Mask; TU Delft


Left: Czech 3D printed CIIRC RP95-3D masks in process; Right: face shield frames by Titan

filter which has been certified as a kit according to EN 140:1999 norm. It meets the same or higher degree of protection as a FFP3 class respirator. The mask can be reused thanks to proven sterilization and disinfection procedures.


Titan Robotics, an industrial 3D printer manufacturer based in Colorado, is using the Atlas pellet extrusion system to speed production of PPE for local health­ care workers. According to the company the Atlas is able to print at a faster rate than usual FDM systems. Fused deposition mode­ ling (FDM) or Fused Filament Fabrication (FFF), is a 3D printing process that uses a continuous filament of a thermoplastic material. The Titan machines use plastic pellets instead of filaments. In this pro­ cess injection molding type pellets are used, which make the printing process faster and cheaper. Each face shield halo only takes 5.5 minutes to print and uses less than 50 cents in material cost, the company says.

Quarantine rooms

There’s much more in the fight against corona where 3D techniques can play a role. Quarantine rooms for instance. Winsun, an architectural 3D printing company based in China, has dis­patched 15 3D printed quarantine rooms to Xianning Central Hospital in the Hubei Province. The hospital is just outside Wuhan, the epicenter of the virus, so it felt the brunt of the force when corona had just started spreading. A lack of hospital beds quickly became a pressing issue for staff as the number of patients

increased exponentially in the first few weeks of the spread. Using solid urban construction waste, Winsun crushed, ground and fabricated small individual quarantine booths to receive the stress on the hospital’s facili­ ties. The rooms’ interiors are decorated and have their own water and electricity supplies. According to Winsun, the prin­ ted walls are three times stronger than traditional concrete walls. Winsun> Much more at 3dprintingindustry>




Ceramic 3D printing aids production of vaccines Earlier this year, Ceramic Tech Today payed attention to the European NES­ SI-project (NESSI is an acronym for ‘New structured substrates for downstream processing of complex biopharma­ ceuticals’, funded from the European Union’s Horizon 2020-programme.) The main goal of this project is to produce new structured adsorbents as selective chromatographic media to separate complex biopharmaceuticals, by cera­ mic-based additive manufacturing (AM); 3D printing. In the combat with COVID-19, 3D printing has proven itself very useful. It’s faster than traditional manufactu­


ring techniques, making it an ideal way to combat the shortage of essential medical devices. Many of the initiatives involve 3D printing plastic materials. But NESSI is using 3D printed ceramics. The NESSIE research was initiated by SINTEF, a Norwegian research organiza­ tion; Lithoz, a world market leader in 3D printing of ceramics; and IBET, a Portu­ guese biopharmaceutical research cen­ ter. genIbet and Cerpotech later joined the consortium, bringing their expertise on manufacturing of biopharmaceuticals and innovative materials. Purification of vaccines is an essential step in the process of developing of new

vaccins. One method of vaccine purifi­ cation is chromatography, a technique that separates a mixture by passing it through a medium in which the mixtu­ re’s components move at different rates. The medium through which the mixture flows is what NESSIE looks to improve by developing novel chromatographic co­ lumns, made of 3D printed ceramics. To create the columns, NESSIE used Lithoz’s ultra-high-resolution ceramic 3D printing technology to create columns with tailored shapes and controlled porosity. Ideally, these specially designed columns will improve separation and reduce the number of necessary purification steps,

INNOVATIVE MATERIALS 3 2020 thus cutting production costs. So far the NESSI-project has successful­ ly produced the first chromatographic supports and will soon test them by pu­ rifying adenoviruses, a group of common viruses that often cause fever, coughs, sore throats, diarrhea, and pink eye, among other illnesses. More at Ceramic Tech Today> And at NESSI>


With ultra-high-resolution ceramic 3D printing technology columns can be made with tailored shapes and controlled porosity



The best homemade face masks consist of two fabrics In the wake of the COVID-19 pandemic, many people are making their own cove­ rings. Researchers report that a com­ bination of cotton with natural silk or chiffon can effectively filter out aerosol particles - if the fit is good. The COVID-19 virus is thought to spread mainly through respiratory droplets when an infected person coughs, snee­ zes, speaks or breathes. These droplets


form in a wide range of sizes, but the tiniest ones, called aerosols, can easily slip through the openings between certain cloth fibers, leading some people to question whether cloth masks can actually help prevent disease. Therefo­ re, Supratik Guha at the University of Chicago and colleagues wanted to study the ability of common fabrics, alone or in combination, to filter out aerosols similar in size to respiratory droplets.

The researchers used an aerosol mixing chamber to produce particles ranging from 10 nm to 6 μm in diameter. A fan blew the aerosol across various cloth samples at an airflow rate corresponding to a person’s respiration at rest, and the team measured the number and size of particles in air before and after passing through the fabric. The best results were obtained with a combination of fabrics. One layer of a tightly woven

INNOVATIVE MATERIALS 3 2020 cotton sheet combined with two layers of polyester-spandex chiffon - a sheer fabric often used in evening gowns filtered out the most aerosol particles (80 - 99 %, depending on particle size), with performance close to that of a N95 mask material1. Substituting the chiffon with natural silk or flannel, or simply using a cotton quilt with cotton-polyes­ ter batting, produced similar results. The researchers point out that tightly woven fabrics, such as cotton, can act as a mechanical barrier to particles, whereas fabrics that hold a static charge, like certain types of chiffon and natural silk, serve as an electrostatic barrier. However, a 1 % gap reduced the filtering efficiency of all masks by half or more, emphasizing the importance of a proper­ ly fitted mask. 1

A N95 mask or N95 respirator is a particulate-filtering facepiece respirator that meets the U.S. National Institute for Occupational Safety and Health (NIOSH) N95 classification of air filtration, meaning that it filters at least 95 % of airborne

particles. It is an example of a mechanical filter respirator, which provides protection against particulates but not against gases or vapors.

More at the university of Chicago>

The findings were published in ACS Nano, titeld ‘Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks’. The article is online>

The experimental setup for the mask test. Different combinations of cloths are placed over the pipe, a fan blows particles at the fabric, and researchers check how many particles made it through the second box



A biodegradable medical mask for COVID-19 Researchers in the BioProducts Institute at the University of British Columbia (UBC) have designed what could be the the world’s first medical N95 mask that’s fully compostable and biodegradable. The idea was to develop an mask that uses local materials, is easy to produce and inexpensive, with the added bonus of being compostable and biodegrada­ ble. According to UBC, The new mask - dubbed Canadian-Mask, or Can-Mask - ticks all those boxes. The mask frame is made entirely from British Columbian wood fibres from sources such as pine, spruce, cedar and other softwoods. There are two proto­ types. One prototype uses a commercial N95 filter on the front of the mask, the other uses a filter specially designed by the UBC team from wood-based products. Both prototypes are currently being tested to ensure they meet health industry specifications for fit and per­


INNOVATIVE MATERIALS 3 2020 meability, with plans to apply for Health Canada certification in the near future. The researchers believe the mask is a good alternative to the synthetic masks currently in use. With millions of dispo­ sable masks and gloves already polluting city sidewalks and potentially entering rivers and oceans, there’s an urgent need for a biodegradable option to avoid making a massive impact on our environ­ ment, the researchers stated. More at UBC>


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Advancing the Green Economy with biotech innovation

TO p Ic c A LE n dA r June

› Topic: Green. Circular. Sustainable

The #EFIB2020 programme will focus on different industry sectors and business areas. Each of the topics will be highlighted with insights, news and a pre-event webinar on sustainability challenges and opportunities after COVID-19. Additionally, virtual 1:1 meetings will be possible 24-hours/day throughout the whole conference week.

› Topic: Fashion & Textiles

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› Topic: Financing & Investing › Topic: Materials & Packaging


› Topic: Food, Feed & Nutrition




› Topic: Bioprocesses & Technologies › Digital EFIB 2020 week: Organised by

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All topics + 1:1 Partne ring Meetings



Graphene fights corona The 2019 coronavirus outbreak (CO­ VID-19) is spreading mainly by respi­ ratory droplets. The use of disposable surgical masks is common for patients, doctors, and even the general public in highly risky areas. However, the current surgical masks cannot self-sterilize in order to reuse or be recycled for other applications. They must either be discar­ ded after each use or sterilized before re-use. Neither option is attractive, since polymer-based masks are difficult to sterilize, while discarding them poses an environmental challenge. A team of researchers at The Hong Kong Polytechnic University (PolyU) developed a graphene coating that makes surgical masks easier to sterilize and re-use. They synthesized graphene using a low-cost laser technique and made the carbon sheet superhydrophobic by controlling the parameters during the laser proces­ sing.


Next, they used a new technique, deve­ loped in their lab, to deposit a few layers of this graphene onto commercial surgi­ cal masks. This new process is known as dual-mode laser-induced forward trans­ fer (LIFT) 1, and it uses a pulsed laser beam with a pulse duration of 10 ns. Since the graphene is superhydrophobic, it is self-cleaning and water droplets freely roll off the surface of the mask before they have time to adhere to it. Another benefit is that the graphene-­ coated masks can simply be sterilized by exposure to sunlight. This because graphene absorbs more than 95 % of sunlight from 300 - 2500 nm, so the coa­ ted masks quickly increase in tempera­ ture, reaching 70 °C after 40 seconds of solar illumination and more than 80 °C after 100 seconds, making the masks reusable after sunlight steriliza­ tion. The PolyU team reported their work in ACS Nano, titled ‘Reusable and Recycla­

ble Graphene Masks with Outstanding Superhydrophobic and Photothermal Performances’. 1

Laser-Induced Forward Transfer is 3D microfabrication technique. It is a digital printing technique that uses a pulsed laser beam as the driving force to project material from a donor thin film toward the receiving substrate whereon that material will be finally deposited as a voxel. (Wiley Online Library)

More about LIFT at Journal of Fluid Mechanics, December 2019> ‘Reusable and Recyclable Graphene Masks with Outstanding Superhydrophobic and Photothermal Performances’ at ACS Nano> More at UBC>




Rotterdam Ahoy 16 & 17 september 2020 8° editie - 10:00-19:00

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Turning sewage water into bioplastics Sewage and industrial wastewater often contain many valuable substances that can be used as raw materials for biobased products. However, this potential is currently not or hardly used, resulting in loss of valuable materials. The INTERREG NWE project WOW! looks into the possibilities to create sustainable value chains from sewage water using these valuable substances. One of the value chains under investigation is the production of PHA (polyhy­ droxyalkanoates), a fully biodegradable bioplastic.

WOW! focuses on the production, extraction and application of PHA. PHA can be produced by bacteria that are often already present in secondary sludge from sewage treatment plants. These bacteria can convert fatty acids into PHA under the right conditions. The PHA is then stored in the bacterial cell as a spare energy source. The fatty acids required for the accumulation of PHA may already be present in sewage or can be produced by partially fer­


menting the primary sludge from the sewage treatment plant. At the Center of Expertise Biobased Economy (CoE BBE) of Avans Hogeschool, in collaboration with the University of Kaiserslautern and Wupperverbandsgesellschaft für integrale Wasserwirtschaft, we are looking at ways to improve the efficiency and stabilization of this PHA production process. Tests are also carried out on the composition and properties of PHA, such as strength, flexibility and colour.

Green extraction method

After production, PHA must be extracted from the bacterial cells before it can be used. A green extraction method has been developed for this at CoE BBE. This method uses dimethyl carbonate, a non-harmful solvent that can also be reused in the extraction process. By looking at different extraction times and different biomass - solvent ratios, it was possible to increase the overall purity of the extracted PHA from 91.2 ± 0.1% to


Figure 1: Schematic overview of production and extraction of PHA

98.0 ± 0.1%. The purity partly determi­ nes the application possibilities of the PHA.

Agricultural film and tree clips

In the second half of 2020, the extrac­ tion of PHA will be tested on a pilot scale in collaboration with Wetsus. The intention is to produce 10 - 20 kg of PHA. This PHA is then tested by Natureplast in

promising applications. Because for the time being the production costs of PHA will be higher than for conventional plas­ tics from petroleum, these opportunities lie mainly in applications where (rapid) degradability offers added value. These are generally one-off applications where collection and/or reuse are difficult or expensive. Think of agricultural foil for, for example, asparagus cultivation or

tree clips that are used when planting or growing trees. The article ‘Optimization of Green Extraction and Purification of PHA Produced by Mixed Microbial Cultures from Sludge’ is available online> The results of the project are regularly published in a newsletter> Team CoE BBE: Jappe de Best, Ischa Lamot, Michiel Mi­ chels, Guilherme Reis, Gabriela Fajardo Partners WOW!: Waterschap Vallei en Veluwe, Wup­ perverbandsgesellschaft für integrale Wasserwirtschaft , University of Kai­ serslautern, University of Luxembourg, VLARIO, Natureplast, Avans University of Applies Sciences, REMONDIS Aqua Industry, VITO, Pulsed Heat, Severn Trent Water, CirTec More at the WOW!-website>

Figure 2: Example of PHA after extraction with dimethyl carbonate



Crystal building: let tiny magnets do the job Tiny magnetic balls are a popular toy for building great 3D shapes. Imagine you’d want to use this principle for building crystal structures by self-assembly, is a spheroid still the best building block? A cuboid, maybe, or a cylinder? Researchers of the University of Twente demonstrate that, in a turbulent water flow, not spheroids but cylinders will form the most regular crystal shape. The work is presented in Science Advances of May 8.

Artificially made crystals, also known as metamaterials, have special properties that can’t be found in their natural coun­ terparts. They can show special mecha­ nical properties or will be able to mani­ pulate light in a special way. They can be used for 3D electronics. The principle of self-assembly means that the basic ‘buil­ ding blocks’ find their own way into the ordered crystal. This can, for example, be done by letting the solvent in which the particles are present, evaporate. Could magnetic interaction be an option for self-assembly, Leon Abelmann1 and his colleagues would like to know. They made millimeter-size objects of various shapes, with a magnetic north and south pole. They released them in an upward


flow of water that not only compen­ sated for gravity but was turbulent as well: the particles, in this way, will ‘feel’ disturbing forces and will be heading to an energy optimum. Just like in the case of the magnetic toy balls, the direction of the magnetic energy works in favour in some cases, and against in other. The particles in the experiments had a preferred direction, determinded by the shape of the shell around the magnet. The researchers studied the three possibilities: the energy in parallel equals the energy in antiparallel, parallel energy is twice the antiparallel or parallel energy is half the antiparallel.


Is the energy in parallel direction larger than in the antiparallel, all shapes tend to form 1D straight lines. That is, except for the spheroids: with a sufficient number of them, they will form rings. Is the preferred direction antiparallel, than 2D structures form, like ‘plates’. If the parallel energy equals the antiparal­ lel, the spheroids cluster together, the cylinders form regular 3D crystal and the cuboids still show various shapes at the same time. Although the cylinder appears to be the best candidate for cre­ ating regular crystals, the structures that are formed with spheroids stay intact in the fluid much longer: not seconds but minutes at least. The researchers assu­


Figure 1. Several 1D, 2D and 3D results, based on the shape and preferred direction of the magnetic objects

me that spheroids are less sensitive for small deviations that lower the magnetic force between the magnets.

Towards smaller sizes

The experiments were done with millimeter size magnetic objects. The outcome, according to Leon Abelmann,

is inspiring for miniaturization. Moving towards micrometer sizes or smaller, can be done using the manufacturing techniques for magnetic random access memories (MRAM). Using self-assembly, it could be possible to create ring-sha­ ped magnetic memories, for example. Apart from that, the researchers expect

that self-assembly can be done in the same way using electric dipoles instead of magnetic ones. This opens the way for creating 3D photonic or electronic crystals. 1 Prof. Dr. Leon Abelmann is working at both the University of Twente (Robotics and Mechatronics group) and KIST Europe (Korean Institute of Science and Technology) in Saarbrücken. The paper ‘Three dimensional self-assembly using dipolar interaction’, by Leon Abelmann, Tijmen Hageman, Per Lötman, Massimo Mastrangeli en Miko Elwenspoek is published online 8 May, in Science Advances, of the American Association for the Advancement of Science (AAAS).> Twente University>

Figure 2. Experimental setup, with the magnetic particles in a turbulent flow inside a cone



A new class of rate-sensitive mechanical metamaterials Researchers at the Department of Biomechanical Engineering of Delft University of Techno­ logy have created a new class of metamaterials that can dynamically switch their mechani­ cal behaviour. It may form the basis for practical applications such as fall-protective clothing for the elderly. The results are to appear in the journal Science Advances on 17 June, titled ‘Strain rate-dependent mechanical metamaterials.’

Metamaterials are artificially crafted ma­ terial structures that derive their proper­ ties from their internal microstructural design, rather than the chemical compo­ sition of the material they are built up from. Metamaterials can be designed to show exceptional properties not found in simple natural materials. For example, while structures that are compressed in one direction are intuitively expected to expand in the opposite direction, a class of metamaterials called auxetic materi­ als are purposefully designed to do the opposite.


Mechanical metamaterial functionalities Thus far, mechanical metamaterial func­ tionalities have not exploited time-de­ pendent effects. This is surprising, says Dr. Shahram Janbaz, researcher at the Biomaterials & Tissue Biomechanics group of TU Delft and first author of the paper, because a lot of flexible materials used to construct mechanical metamaterials, such as polymer-based plastics, show mechanical behaviour that depends on the speed with which they are deformed. Viscoelastic materials, when strained, undergo slow changes that dissipate energy. Their mechanical

response, therefore, depends on how fast you deform them. The team, led by Prof. Amir Zadpoor, now brings the time dimension into the mechanical metamaterial toolbox, creating what could be considered a new class of metamaterials that can dynami­ cally switch their mechanical behaviour. The team constructed tall pillars that consist of two different materials: one side is made from a material that res­ ponds to the speed of deformation while the material of other side does not care about how fast it is deformed. When applying a compressive force along the

RESEARCH long axis direction of this ‘bi-beam’, the elasticity of both materials ensures that it doesn’t break but rather buckles.

Strange properties

The researchers showed that the bi-beam predictably buckles to either the left or the right side depending on the speed of compression. This strain rate-dependent behaviour of bi-beams is the key to creating new materials with strange properties not seen before. ‘All you need to do is to find a clever way of assembling bi-beams and odds are pretty good that you find mechanical behaviour that has never been reported before’, says Zadpoor. Janbaz: ‘For example, we connected two parallel, mirrored bi-beams to each other through stiff connectors as a basic unit cell that can be repeated in all directions to create a three-dimensio­ nal metamaterial lattice structure. We found that, by increasing the strain rate, the mechanical behaviour of such a cell switched completely from auxetic to conventional.’ Videos accompanying the publication show how a lattice made up of intercon­ nected unit cells shrinks for low com­ pression speeds and expands for high speeds.


One of potential applications of me­ tamaterials showing such switching behaviour is that of protection against falls. Imagine a wearable layer. Under normal circumstances, it is soft and fol­ lows the movements of the body. When an impact occurs, the material switches its behaviour, acting as a shock absorber. This might help people suffering from osteoporosis, where bone fractures con­ stitute a major complication. The researchers also created bi-beam lattices that are programmed to become less stiff if they are strained more quick­ ly. This behaviour can be called negative viscoelasticity and has not been obser­ ved before in solids. While it might be difficult to create much smaller bi-beams of the same design as the centimetre-sized model systems tested here, the researchers see possi­ bilities to use 3D printing techniques to create lattices of tiny bi-beams. The researchers are excited about the potential of their bi-beam design. They expect that this basic element can be used to create a rich variety of mechani­ cal behaviour.

Prof.dr. A.A. Zadpoor +31 15 27 81021 A.A. S. Janbaz +31 15 27 83133 Application of bi-beams for designing metamaterials and mechanisms with novel properties and functionalities. A circular arrangement of bi-beams was used to transform axial compression to either clockwise or counterclockwi­ se rotation, depending on the applied strain rate. Moreover, the stiffness of the rotational mechanism is highly depen­ dent on the applied strain rate. (Photo credit: Shahram Janbaz, Delft University of Technology) The article ‘Strain rate-dependent mechanical metamaterials’ is online>

Text: TU Delft> Video

A circular arrangement of bi-beams was used to transform axial compression to either clockwise or counterclockwise rotation, depending on the applied strain rate. Moreover, the stiffness of the rotational mechanism is highly dependent on the applied strain rate (Photo credit: Shahram Janbaz Delft University of Technology)



Complex soft robotic functions formed in liquid crystal networks Since their development at the end of last century, reactive mesogens (RM’s) form a versa­ tile class of soft matter materials that have found their way to a wealth of applications. The use of RM’s for soft robotics applications is nowadays studied by many academic and indus­ trial institutes. For instance, at Eindhoven University of Technology, self-sustaining oscilla­ tors, cilia based micro-transport devices and haptic surfaces have been developed. In this article we discuss some of our newest developments on responsive liquid crystal polymer materials, giving a preliminary view on the future of RM’s with advanced applications in the fields of oscillatory films, smart coatings, soft robotics and haptics. 34 | INNOVATIVE MATERIALS 3 2020

RESEARCH Since their development in the 80’s of last century, reactive mesogens (RM’s) form a versatile class of soft matter materials that have found their way to a wealth of applications. The frozen-in molecular order of the polymer net­ works that they form upon polymerizati­ on brought a new dimension into liquid crystal technologies. Initially developed for their use as low shrinkage, low thermal stress coatings, the RM’s de­ monstrated their function especially in optical applications. The large, tempera­ ture-stable and adjustable birefringence was adopted by the display industry for many purposes, varying from viewing angle enhancement to optical-retarder based 3D imaging optics. Presently, advanced optical applications for aug­ mented reality and astronomy lenses are drawing much attention as well as their use to stabilize special liquid crystal effects for smart windows and dedicated display types. The use of RM’s for soft robotics appli­ cations is nowadays studied by many academic and industrial institutes. At Eindhoven University of Technology, we developed self-sustaining oscillators, cilia based micro-transport devices and haptic surfaces. Triggered by heat, light or humidity the polymers change shape, surface structure or porosity. Films deform from a flat to a complex, but pre-designed, shape with prospects to light-triggered origami and self-fol­ ding plastic elements. A completely new development relates to coatings that switch their surfaces from flat to corrugated with a preset topography. Or in a different design from dry to wet by controlled secretion of liquid. Properties that enable controlling properties as

friction, grip, lubrication, stick, soil rejec­ tion, particle manipulation, etc.

Liquid crystal polymers networks

Liquid crystal polymer networks (LCNs) are polymers with a well-controlled molecular positioning into all three dimensions. They exhibit unusual, but very accurately adjustable and addres­ sable optical, electrical and mechanical properties. The underlying principle of employing LCNs for morphing is their capability to change the molecular order, both in number (order parameter) and in direction (director). The thereby built-up stresses lead to an anisotropic dimensi­ onal change of the LCNs with a contrac­ tion along the molecular orientation and expansions perpendicular to it (Figure 1a). Based on this principle, various stimuli ranging from temperature, light to humidity are demonstrated.

Dynamic surface topographies

When a thin film of the LCN is restric­ ted by adhesion to a solid substrate the director related dimensional changes lead to the creation of surface protrusi­ ons with diverse topographic structures in thin coatings. During the 4TU.HTM project ‘Communicating Surfaces’, we discovered that by bringing the molecu­ lar deformation, either triggered by light or by an electrical field, in resonance with the eigenfrequency of the polymer network strongly enhances the forma­ tion of extra temporal free volume and the corresponding pronounced forma­ tion of topographies. In a light driven LCN, this is achieved by accelerating the oscillatory trans-cis isomerization of the actuating azobenzene by choosing light that addresses both isomeric states. For electric field actuation we use an AC voltage to exert an oscillatory stress on the LCN main chains (Figure 1b). The AC

Figure 1a. Soft robotic functions created in a liquid crystal polymer network. (a) Schematic representation of anisotropic deformation of LCNs upon reduction of order parameter. (b) Electric-driven dynamic surface topographies formed in a homeotropically aligned liquid crystal network. (c) Liquid secretes at the coating surface upon illuminated with UV light



field is generated from the interdigitated electrodes buried under the LCN coa­ tings. The mesogenic rods are thereby continuously changing their initial orien­ tation and packing. This leads to the desired free volume expansion of around 10%. The advantage of this principle compared with for instance electroactive polymers is that there is no need for a compliant electrode deposited on top of the coating and relatively low voltages are required.

changed by secreting and uptaking liquids in a controlled manner. Also here we use various triggers, e.g. electrici­ ty, light irradiation, temperature, or a combination of them. The coating itself

is solid and the liquid is stored in its deformable nanometer to microme­ ter-sized pores. The pores in the coating are made by a controlled phase separa­ tion process of a liquid crystal porogen

Figure 1b (video)

Figure 1c (video)

Liquid secretion on demand

In another approach, we developed coatings whose surface properties are

Smart coatings causes goose bumps Danqing Liu and her colleagues at Eindhoven University of Technology are working hard on a coating that can change shape. This technology makes all kinds of things possible, from Mars rovers and solar panels that can autonomously shake off sand, to Braille on your mobile phone, surgical instruments that provide feedback to the doctor, or VR gloves that help you to throw a ball really well. The possibilities of this technology are endless. For example you can also make robots that can feel and can get goose bumps, enabling them to communicate with each other in new ways. This could also be useful in all kinds of training situations where touch plays a role, such as physiotherapy or first-aid courses.!/8581/smart_coating/


RESEARCH Part of this research has been performed within the framework of the 4TU. High-Tech Materials research programme ‘New Horizons in designer materials’ (> More about the project ‘Communcating Surfaces’> References

during a polymerizing liquid crystal po­ lymer network (LCN). Upon compressing the skin by light or by an electrical field, the pore dimensions will be reduced which squeezes out the initially locked liquid at the coating surface (Figure 1c). The released fluid can be re-absorbed benefitting from the elasticity of the polymer in combination with capillary forces when the trigger is switched off or on demand by an alternate trigger that restores the pore dimensions. Alter­ natively, the liquid can be exchanged for another liquid depending on the desired functionality. We demonstrated that the released liquid changes and controls

the tribological behavior of the coating surface. In addition, when the coating is brought into contact with an opposing surface the light-controlled release of fluid may induce capillary bridging thus providing a strong adhesion between the two coatings.

D. J. Broer and G. N. Mol, Polym. Eng. Sci. 31, 625 (1991). R. A. M. Hikmet, B. H. Zwerver and D. J. Broer, Polymer 33, 89 (1992). H.F. Yu and T. Ikeda, Adv. Mater. 23, 2149 (2011). A. Jákli, I. C. Pintre, J. Luis Serrano, M. Blanca Ros and M. Rosario de la Fuente, Adv. Mater. 21, 3784 (2009). O. M. Wani, H. Zeng, P. Wasylczyk, A. Priimagi, Adv. Opt. Mater. 6, 1700949 (2018). W. Wu, L. Yao, T. Yang, R. Yin, F. Li and Y. Yu, J. Am. Chem. Soc. 133, 15810-15813 (2011). G. Babakhanova, T.Turiv, Y.Guo, M. Hendrikx, Q. Wei, A.P.H.J. Schenning, D.J. Broer, O. D Lavrentovich, Nat. commun.9, 1130 (2018). W. Zhou, T. Kobayashi, H. Zhu, and H. F. Yu, Chem. Commun., 47, 12768–12770 (2011). J.S. Evans, P.J. Ackerman, D.J. Broer, J. Lagemaat and I.I. Smalyukh, Phys. Rev. E 87, 032503-1 (2013). M. Warner, C.D. Modes and D. Corbett, Proc. R. Soc. A 466, 2975 (2010). M. Camacho-Lopez, H. Finkelmann, P. Palffy-Muhoray and M. Shelley, Nat. Mater. 3, 307 (2004). T.J. White, S.V. Serak, N.V. Tabiryan, R.A. Vaia and T.J. Bunning, J. Mater. Chem. 19, 1080 (2009). Y. Takeoka, M.Teshima, and T. Seki, Chem. Commun., 54, 2607-2610 (2018). K. Mukai, M. Hara, S.Nagano, and T. Seki, Angew. Chem. Int.Ed. 55, 14028-14032 (2016). T. Kosa, L. Sukhomlinova, L. Su, B. Taheri, T.J. White and T.J. Bunning, Nature 485, 347 (2012). T. Ozawa, M. Kondo, J. Mamiya and T. Ikeda, J. Mater. Chem. C 2, 2313-2315 (2014). M. Yamada, M. Kondo, J. Mamiya, Y. Yu, M. Kinoshita, C. J. Barrett and T. Ikeda, Angew. Chem. Int. Ed., 47, 4986-4988 (2008). T. Ube, K. Kawasaki and T. Ikeda, Adv. Mater.28, 8212-8217 (2016). D. Liu and D.J. Broer, Nat. Commun. 6, 8334 (2015). D. Liu, N. B. Tito and D.J. Broer, Nat. Commun. 8, 1526 (2017). A. H. Gelebart, D. Liu, D. J. Mulder, K.H. J. Leunissen, J. van Gerven, A. P. H. J. Schenning, D. J. Broer, Adv. Funct. Mater. 28, 1705942 (2018).

Danqing Liu, in cooporation with Dick Broer Eindhoven University of Technology, Department of Chemical Engineering and Chemistry E-mail:



Enterprise Europe Network (EEN) supports companies with international ambitions The Enterprise Europe Network (EEN) is an initiative of the European Com­ mission that supports entrepreneurs in seeking partners to innovate and do business abroad. The Network is active in more than 60 countries worldwide. It brings together 3,000 experts from more than 600 member organisations – all renowned for their excellence in business support.


Every company can participate by adjus­ ting its profile to the database. This com­ pany will be brought to the attention in the country in which it wants to become active. At the same time it is possible to search for partners. EEN advisers actively assist in compi­ ling the profile, which is drawn up in a certain format. The EEN websites also contain foreign companies that are looking for Dutch companies and organi­ zations for commercial or technological cooperation. The EEN advisers support the search for a cooperation partner by actively deploying contacts within the network. In addition, Company Missions

and Match Making Events are regularly organized. All these services are free of charge. There are five types of profiles:

• Business Offer:

the company offers a product

Video: How Enterprise Europe Network works

• Business Request:

the company is looking for a product

• Technology Offer:

the company offers a technology

• Technology Request:

the company is looking for a tech­ nology

• Research & Development Request:

the organization seeks cooperation for research

When a company has both a Business Offer and a Business Request (or another combination), two (or even more if ap­ plicable) profiles are created. The profile includes the most essential

information about the nature of the sup­ ply or demand, the ‘type of partner’ that is intended and the expected cooperati­ on structure. Get in touch with your local network contact point by selecting the country and city closest to where your business is based. They can help you with advice, support and opportunities for internatio­ nal partnerships. For sustainable building and the creative industry, contact ir. drs. Hans Kamphuis: T: +31 (0) 88 042 1124 M: 06 25 70 82 76 E: For Materials contact Nils Haarmans: T: +31 (0) 88 062 5843 M: 06 21 83 94 57 More information websites can be found at the Europe Network websites:


ENTERPRISE EUROPE NETWORK The Enterprise Europe Network Materials Database: Request for partnership: July 2020. Intrested? contact>

Romanian company specialised in manufacturing of thermo and hydro insulation systems is looking for partners under distribution service and/or manufacturing agreement North-Eastern Romanian company with over 25 years experience as manufacturer and distributor of fiberglass reinforce­ ment mesh, drainage and waterproofing systems is interested to cooperate with foreign partners to expand on new markets, under distribution and/or manufacturing service agreement. BORO20190910001

Slovenian company specialised in processing and injection moulding of technically advanced plastic products is offering its services under manufacturing agreement A company from Slovenia is specialised in injection moulding of plastic products with the latest machinery and self-made tools. With laboratory certified materials they can produce diverse plastic products for different sectors like automotive, con­ struction, appliances and ventilation systems. Under manufacturing agreement, they are looking for partners that require temporary or regular production of plastic products according to international standards and certificates. BOSI20200527001

Aerospace composite companies sought for Eureka multilateral advanced materials call partner search for 4D x-ray visualisation of porosity within thermoplastic and thermoset composite materials in compression moulding A Midlands based UK University is seeking partners to join their consortium for the Eureka Multilateral Advanced Materials call. They are specifically interested in the utilisation of 4D x-ray visualisation to build an understanding of the sources of material inconsistency and failure. The are looking for aerospace composite companies that are interested in building aircraft structures from PEEK (Polyetheretherketone) and/or carbon fibre. RDUK20200430001

Eurostars-Eureka: Designer of ultra-thin tiles veneer looks for ultra-thin stone manufacturer A Belgian SME has developed a process to manufacture ultra-thin tiles made of natural stone with high impact resistance. The goal of the project is to develop this innovative product until the commercialization stage, currently at demonstration phase. The expertise sought is a ultra-thin stone manufacturer with an ambition to innovate to produce the testing samples for this research project. Research cooperation is envisaged under the Eurostars programme. Call deadline: 3rd September 2020. RDBE20200407001

Looking for alternative technologies/chemical solutions to replace the use of per- and polyfluoroalkyl substances (PFAS) A Swedish manufacturer of disposable packaging and take-away products is looking for alternative technologies/chemical so­ lutions to replace the use of per- and polyfluoroalkyl substances (PFAS) in their fiber-molded products. A PFAS-free solution should provide barrier properties such as oil-, grease- and water-repellence. The company is looking for solutions that are close to being commercially available and is seeks collaborations with chemical providers under a manufacturing agreement. TRSE20200128002


ENTERPRISE EUROPE NETWORK The Enterprise Europe Network Materials Database: Request for partnership: July 2020. Intrested? contact>

A Japanese company is seeking 3D printing technology for building constructions to distribute in Japan The Japanese company is specialized in finance and real-estate markets and is aiming to distribute leading 3D printing technology specific to building constructions in Japan. The constructions should meet the quality standards of Japan’s building sector. The partnership with a potential partner could be made within the frame of a commerci­ al agency agreement, a distribution service agreement, licensing or services agreements.

Enterprise Europe Network at Building Holland Innovation Expo Cirkelstad The Enterprise Europe Network will be present at the Innovation Expo of Cirkelstad during Building Holland, from 27 to 29 October. Many innovations are shown here and match interviews take place. You can register for these match conversations soon.


EVENTS The corona crisis makes it uncertain whether events will actually take place on the scheduled date. Many events are postponed, sometimes to 2021. The Agenda below shows the state of affairs as of May 2020. For recent updates: Challenging Glass, Gent Webinar - 4 September 2020

HK Härterei Kongress 2020 20 - 22 October 2020, Keulen

Architect@Work 2020 16 - 17 September 2020, Rotterdam

Glasstec 2020 20 - 23 October 2020, DĂźsseldorf

CeramicsExpo 2020 22 - 23 September 2020, Cleveland

81th Congress on Glass Problems 26 - 29 October 2020, Columbus

Aluminium Association Annual Meeting 23 - 25 September 2020, Wasington DC

SurfaceTechnology GERMANY, 27 - 29 October 2020, Stuttgart

SE Conference 20 Amsterdam 30 september - 1 October 2020, Amsterdam

EuroBLECH 2020, 27 - 30 October 2020, Hannover

EFIB 2020 5 - 6 Oktober 2020, Frankfurt am Main

iENA Nuremberg 29 oktober - 1 November 2020, Neurenberg

Plastics Recycling World Exhibition 2020 6 - 7 Oktober 2020, Essen

Composites for Europe 10 - 12 November 2020, Stuttgart

Techni-Mat 2020 7 - 8 October 2020, Kortrijk

GrindTec 2020 10 - 13 November 2020, Augsburg

Architect@Work 2020 Deutschland 7 - 8 October 2020, Berlin

Formnext 2020, 10 - 13 November 2020, Frankfurt

Nationale Staalbouwdag 2020 13 October 2020, Rotterdam

BOUWXPO 13 - 15 November 2020, Kortrijk

Fakuma 2020 13 - 17 October 2020, Friederichshafen

Precisiebeurs 2020 18 - 19 November 2020, Veldhoven


Innovative Materials, the international version of the Dutch magazine Inno­ vatieve Materialen, is now available in English. Innovative Materials is an in­ teractive, digital magazine about new and/or innovatively applied materials. Innovative Materials provides information on material innovations, or innovative use of materials. The idea is that the ever increasing demands lead to a constant search for better and safer products as well as material and energy savings. Enabling these innovations is crucial, not only to be competitive but also to meet the challenges of enhancing and protecting the environment, like durability, C2C and carbon footprint. By opting for smart, sustainable and innovative materials constructors, engi­ neers and designers obtain more opportunities to distinguish themselves. As a platform Innovative Materials wants to help to achieve this by connec­ ting supply and demand. Innovative Materials is distributed among its own subscribers/network, but also through the networks of the partners. In 2019 this includes organisati­ ons like M2i, MaterialDesign, 4TU (a cooperation between the four Technical Universities in the Netherlands), the Bond voor Materialenkennis (material sciences), SIM Flanders, FLAM3D, RVO and Material District.