18 minute read
Digory: 3D printed ivory
from IM20213EN
3D-printed ivory
In 1989, the trade in ivory was banned internationally. Since then, to restore ivory parts of ancient artifacts, substitute materials - such as bones, shells or plastic - must be used. However, there has not been a really satisfactory solution so far. TU Wien (Vienna) and the 3D printing company Cubicure GmbH, created as a spin-off of TU Wien, have now developed a high-tech substitute in cooperation with the Archdiocese of Vienna’s Department for the Care of Art and Monuments and Addison Restoration: the novel material ‘Digory’ (digital ivory) consists of synthetic resin and calcium phosphate particles. It is processed in a hot, liquid state and hardened in the 3D printer with UV rays, exactly in the desired shape. It can then be polished and colour-matched to create a deceptively authentic-looking ivory substitute. The research project began with the res-
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tauration of a 17th-century state casket in the parish church of Mauerbach by team prof. Jürgen Stampfl from the Institute of Materials Science and Technology at TU Wien. The valuable casket was decorated with small ivory ornaments, some of which have been lost over time. The question was whether they could be replaced with 3D printing technology.
Through numerous experiments, the team from TU Wien and Cubicure succeeded in finding the right mixture: tiny calcium phosphate particles with an average diameter of about 7 µm were embedded in a special resin, together with extremely fine silicon oxide powder. The mixture is then processed at high heat in Cubicure’s 3D printers using the hot lithography process. Layer by layer, the material is cured with a UV laser until the complete object is finished. By adding the right amount of calcium phosphate the material has the same translucent properties as ivory. The material contained 55 wt.% (30 vol.%) of TCP (tricalcium phosphate) particles to match the translucency of natural ivory. Measurements revealed that the density and hardness of Digory (1.78 ± 0.02 g cm−3; 35.7 ± 1.3 HV at a load of 200 g) is comparable to the density and hardness of ivory found in literature (1.7 - 1.9 g cm−3; ~35 HV). Afterwards, the colour of the object can be touched up - the team achieved good results with black tea. According to theTU Wien, the new material ‘Digory’, not only is a better, more beautiful and easier to work with substitute for ivory available than before, the 3D technology also makes it possible to reproduce the finest details automatically. Instead of painstakingly carving them out of ivory substitute material, objects can now be printed in a matter of hours.
The paper ‘Developing an ivory-like material for stereolithography-based additive manufacturing,’ was published in Applied Materials Today, June 2021.
TU Wien>
The dates and location of MaterialDistrict 2021 are known. The event will move from March to September 15, 16 & 17 and from Rotterdam to Utrecht (Werkspoor Cathedral).
MaterialDistrict Utrecht (formerly Material Xperience) is the only event in the Netherlands that offers material manufacturers and specifiers of materials in all sectors of spatial design (interior, architecture, garden & landscape, leisure, furniture & interior construction and exhibition, stage & decor).
Click here for more information
New bio-inspired, light-capturing nanomaterials
Inspired by nature, researchers at Pacific Northwest National Laboratory (PNNL), along with collaborators from Washington State University, created a novel material capable of capturing light energy making it suitable for photovoltaic applications. The results of this study were published May 14, 2021, in Science Advances.
Nature provides beautiful examples of hierarchically structured hybrid materials such as bones and teeth. These materials typically showcase a precise atomic arrangement that allows them to achieve many exceptional properties, such as increased strength and toughness. Materials scientist Chun-Long Chen and his collaborators created a new material that reflects the structural and functional complexity of natural hybrid materials. This material combines the programmability of a protein-like synthetic molecule with the complexity of a silicate-based nanocluster to create a new class of highly robust nanocrystals. They then programmed this 2D hybrid material to create a highly efficient artificial light-harvesting system.
Though these types of hierarchically structured materials are exceptionally difficult to create, the team managed to synthesize a sequence-defined molecule capable of forming such an arrangement. The researchers created an altered protein-like structure (peptoid) and attached a precise silicate-based cage-like structure (polyhedral oligomeric silsesquioxane, abbreviated POSS) to one end of it. They then found that, under the right conditions, they could induce these molecules to self-assemble into perfectly shaped crystals of 2D nanosheets. This eventually resulted in a cell-membrane-like composition similar to that in natural hierarchical structures, while retaining the high stability and enhanced mechanical properties of the individual molecules. Subsequently they programmed the material to include special functional groups at specific locations and intermolecular distances. Because these nanocrystals combine the strength and stability of POSS with the variability of the peptoid building block, the programming possibilities were endless. Once again looking to nature for inspiration, the scientists created a system that could capture light energy much in the way pigments found in plants do. The scientists eventually succeeded in constructing a system that could capture light energy. The system exhibited an energy transfer efficiency of over 96 %, making it one of the most efficient aqueous light harvesting systems of its kind reported so far.
More at PNNL>
The paper ‘Programmable two-dimensional nanocrystals assembled from POSS-containing peptoids as efficient artificial light-harvesting systems’ is online>
POSS-peptoid molecules self-assemble into rhomboid-shaped nanocrystals (Illustration by Stephanie King, Pacific Northwest National Laboratory)
How to solve the autogenous shrinkage problem of geopolymers/alkali-activated concrete?
Geopolymers or alkali-activated materials (AAMs), as ecofriendly alternatives to Ordinary Portland Cement (OPC), have attracted increasing attention of researchers in the past decades. Unlike cement, which requires calcination of limestone, AAMs can be made from industrial by-products, or even wastes, with the use of alkali-activator. The production of AAMs consumes 40% less energy and emits 25 - 50% less CO2 compared to the production of OPC. Despite the eco-friendly nature of AAMs, doubts about these materials as an essential ingredient of concrete exist, regarding, for example, their volume stability. Autogenous shrinkage is the reduction in volume caused by the material itself without substance or heat exchange with the environment. If the autogenous shrinkage of a binder material is too large, cracking might happen, which will seriously impair the durability of concrete.
The aim of the study of Dr. Zhenming Li (TU Delft) was, therefore, set to understand and mitigate the autogenous shrinkage and the cracking tendency of AAMs. At first, the autogenous shrinkage of AAMs is studied experimentally. It is shown that self-desiccation is not the exclusive mechanism of autogenous shrinkage of AAMs. Other driving forces, such as the steric-hydration force between colloids associated with the change in ion concentrations in the pore solution, also play a role, especially in the very early age. Besides, AAMs show pronounced viscoelasticity, which means a large time-dependent deformation or creep. Based on the clarified mechanisms, two strategies are proposed aiming at mitigating the driving forces of autogenous shrinkage: internal curing with superabsorbent polymers (SAPs) and the incorporation of metakaolin (MK). Experiments in this study prove that the strategies proposed above are very effective to reduce the cracking tendency of alkali-activated slag and fly ash concrete. This result indicates that SAPs and MK can be promising ingredients for large-scale use in AAMs mixtures. The numerical approaches developed in this study are also useful in future studies or applications to estimate the creep and relaxation in AAMs.
Figure 2. A schematic diagram of the stress development and the resultant cracking of concrete due to restrained shrinkage
Figure 1. Schematic representation of cracking induced by restrained shrinkage
The PhD research of dr. Zhenming Li was carried out in the Department of Materials, Mechanics, Management & Design, Civil Engineering and Geosciences, Delft University of Technology. He was supervised by dr. Guang Ye and prof.dr.ir. Klaas van Breugel. He successfully defended his thesis on the 15th of March 2021. The title of his dissertation is: ‘Autogenous shrinkage of alkali-activated slag and fly ash materials: From mechanism to mitigating strategies.’
The thesis can be found here>
Orange peel makes transparent wood 100 percent renewable
Five years ago, scientists at the Swedish KTH Royal Institute of Technology developed transparent wood; a remarkable material that allows light to pass through and also was able to store heat. (Innovative Materials 2016, volume 3.) Recently, they have taken it to another level by making their composite 100 percent renewable and even more translucent. The key to making wood into a transparent composite material is to strip out its lignin, the major light-absorbing component in wood. However, lignin also gives wood its strength. So the empty pores left behind by the absence of lignin need to be filled with something that restores the wood’s strength and allows light to permeate.
In early versions of the composite, researchers at KTH’s Wallenberg Wood Science Center used fossil-based polymers. Now, the researchers have successfully tested an eco-friendly alternative: limonene acrylate, a monomer made from limonene. Limonene acrylate is made from renewable citrus, such as peel waste that can be recycled from the orange juice industry.
The new composite offers optical transmittance of 90 percent at 1.2 mm thickness and remarkably low haze of 30 percent, the researchers report. Unlike other transparent wood composites developed during the past five years, the material developed at KTH is intended for structural use. It shows heavy-duty mechanical performance: with a strength of 174 MPa (25.2 ksi) and elasticity of 17 GPa (or about 2.5 Mpsi). According to the researchers, this new technology could enable a yet unexplored range of applications, such as smart windows, wood for heat-storage, wood that has built-in lighting function - even a wooden laser.
Swedish KTH Royal Institute of Technology>
The results were recently published in Advanced Science, titled ‘High performance, fully bio-based, and optically transparent wood biocomposites,’ Advanced Science, DOI: 10.1002/ advs.202100559. The article is online>
The latest version of transparent wood developed at KTH is more translucent, and it is made with renewable polymer (Photo: Céline Montanari)
From CO 2 to SiC
Plants are unparalleled in their ability to capture CO2 from the air, but this benefit is temporary, as leftover crops release carbon back into the atmosphere, mostly through decomposition. Researchers of Salk Institute for Biological Studies (California) have proposed a more permanent, and even useful, fate for this captured carbon by turning plants into a valuable industrial material silicon carbide (SiC), offering a strategy to turn an atmospheric greenhouse gas into an economically and industrially valuable material. SiC is an ultrahard material used in ceramics, sandpaper, semiconductors and LEDs.
In a new study, published in the journal RSC Advances on April 27, 2021, scientists at Salk transformed tobacco and corn husks into SiC and quantified the process with more detail than ever before. The Salk team transformed plant material into SiC in three stages. First, the researchers grew tobacco,
Scanning electron microscopy image of SiC petrified corn husks (Credit: UC San Diego)
chosen for its short growing season, from seed. They then froze and ground the harvested plants into a powder and treated it with several chemicals including a silicon-containing compound. In the third and final stage, the powdered plants were petrified (turned into a stony substance) to make SiC, a process that involves heating the material up to 1600 °C.
Through elemental analysis of the plant powders, the authors measured a 50,000-fold increase in sequestered carbon from seed to lab-grown plant, demonstrating plants’ efficiency at pulling down atmospheric carbon. Upon heating to high temperatures for petrification, the plant material loses some carbon as a variety of decomposition products but ultimately retains about 14 percent of the plant-captured carbon. The researchers calculated that the process to make 1.8 g of SiC required about 177 kW/h of energy, with the majority of that energy (70 percent) being used for the furnace in the petrification step. The authors note that current manufacturing processes for SiC carry comparable energy costs. So while the production energy required means that the plant-to-SiC process isn’t carbon neutral, the team suggests that new technologies created by renewable energy companies could bring down energy costs. Next, the team hopes to explore this process with a wider variety of plants, in particular plants like horsetail or bamboo, that naturally contain large amounts of silicon.
More at Salk>
The paper ‘Plant-based CO2 drawdown and storage as SiC’ (DOI: 10.1039/d1ra00954k) is online>
Enterprise Europe Network (EEN) supports companies with international ambitions
The Enterprise Europe Network (EEN) is an initiative of the European Commission 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.
Database
Every company can participate by adjusting its profile to the database. This company 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 compiling the profile, which is drawn up in a certain format. The EEN websites also contain foreign companies that are looking for Dutch companies and organizations 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
• Business Request: the company is looking for a product
• Technology Offer: the company offers a technology
• Technology Request: the company is looking for a technology
• 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 applicable) profiles are created. The profile includes the most essential information about the nature of the supply or demand, the ‘type of partner’ that is intended and the expected cooperation 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 international 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: hans.kamphuis@rvo.nl
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:
Video: How Enterprise Europe Network works
www.enterpriseeuropenetwork.nl
http://een.ec.europa.eu
The Enterprise Europe Network Materials Database: Request for partnership: July 2021.
Intrested? contact hans.kamphuis@rvo.nl>
British provider of sustainable packaging solutions seeks a manufacturer of compostable packaging
A UK supplier of biodegradable and fully compostable packaging products seeks partners that are able to produce air cushion and air quilt packaging, shrink wrap, and shipping bags from compostable materials under the framework of a manufacturing agreement.
German company seeks manufacturer for wooden brush handles and source for raw materials
The German company became one of the European leading manufacturers of fine brushes. The company’s products are used for hair and body, the household and for pets. The company is looking for a manufacturer in the framework of a manufacturing agreement to cover its additional material needs.
Spanish architecture, interior design and furniture design company is looking for manufacturers and suppliers of sustainable, technological and singular products/services
A Spanish architecture, interior design, branding and furniture design company is looking for manufacturing and supplying agreements to acquire innovative products/services for its projects. The SME carries out disruptive sustainable projects in the tourism and residential sector, applying technological innovation when possible. The company is committed to take part in projects that contribute to energy saving and are beneficial to the environment.
Danish supply agencies seeks innovative and high-quality supplier of roofing shingles
A Danish company operating as local sales representative/sales platform for international suppliers addressing the building and construction industry is looking for new suppliers of high quality and CE-marked roofing felt/composite shingles for building and construction. The company offers access to the Danish and possibly also Scandinavian markets through a solid network of contractors as well as key resellers in the market(s), via a supplier agreement.
A German online food delivery service is looking for a porcelain manufacturer to produce custom food to-go packaging according to design requirements
A German sustainable online food delivery service is looking for a supplier/manufacturer of porcelain that can produce porcelain to-go packaging according to the design requirements set by the German company. The company is interested in partnerships in the frame of a manufacturing agreements.
The corona crisis makes it uncertain whether events will actually take place on the scheduled date. Many events are postponed or online. The Agenda below shows the state of affairs as of July 2021. For recent updates: www.innovatievematerialen.nl
Additive Manufacturing Forum 2021 21 - 22 July 2021, Berlin
Kunststoffen 2021 15 - 16 September 2021, Den Bosch
Materials+Eurofinish+Surface 15 - 16 September 2021, Den Bosch
Material District Utrecht 15 - 17 September 2021, Utrecht
Nederlandse Metaaldagen 15 - 17 September 2021, Den Bosch
Plastics Recycling World Exhibition 2021 29 - 30 September 2021, Essen
Vitrum 2021 5 - 8 October 2021, Milano
Deburring EXPO 12 - 14 October 2021, Karlsruhe
Fakuma 12 - 16 October 2021, Friederichshafen
Euro PM2021 Congress and Exhibition 17 - 20 October 2021, Lissabon
Glazing Summit 2021 21 October 2021, Birmingham Architect@Work 2021 Belgium 21 - 22 October 2021, Kortrijk
iENA Nuremberg 4 - 7 November 2021, Nuremberg
BOUWXPO 12 - 14 November 2021, Kortrijk
Fastener Fair Stuttgart 2021 9 - 11 November 2021, Stuttgart
3D Delta week 6 - 10 December 2021
Digital BAU 15 - 17 February 2022, Keulen
Solids 2022 16 - 17 February 2022, Dortmund
Ulmer Betontage 2022 22 - 24 February 2022, Ulm
ESEF 2022 15 - 18 March 2022, Utrecht
JEC World 2022 8 - 10 March 2022, Paris-Nord
BLE.CH 2022 8 - 10 March 2022, Bern
Innovative Materials, the international version of the Dutch magazine Innovatieve Materialen, is now available in English. Innovative Materials is an interactive, 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, engineers and designers obtain more opportunities to distinguish themselves. As a platform Innovative Materials wants to help to achieve this by connecting supply and demand.
Innovative Materials is distributed among its own subscribers/network, but also through the networks of the partners. In 2021 this includes organisations 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.
