Karan Revankar|Dissertation|Biomimetic Exploration of Daylight Responsive Origami Pneumatic System

Biomimetic Exploration of Daylight-Responsive Origami Pneumatic System

DissertationSubmitted in the partial fulfilment of the requirements for submission of Dissertation for Bachelors of Architecture

By Karan Revankar Reg. No. 1190100843

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Shri Kapil Natawadkar Designation Assistant Professor

Department of Planning/Architecture

School of Planning and Architecture, Vijayawada November, 2023

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This is to certify that the Dissertation titled “Biomimetic Exploration of DaylightResponsive Origami Pneumatic System” has been submitted by Karan Revankar (Reg. No. 1190100843) at the Department of Architecture, towards partial fulfilment of the submission for Bachelors of Architecture. This is a bonafide work of the student.

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DISCLAIMER

The content produced in the dissertation report is an original piece of work and takes due acknowledgement of referred content, wherever applicable. The thoughts expressed herein remain the responsibility of the undersigned author and have no bearing on or does not represent those of School of Planning and Architecture, Vijayawada.

Name: Karan Revankar

Reg. No. 1190100843 2020-21

Bachelors in Architecture

Department of Architecture

Date: DD-MM-YYYY

Abstract

"Biomimetic Exploration of Daylight-Responsive Origami Pneumatic System," embarks on a transformative journey at the nexus of architecture, biomimicry, and sustainable design. In a world where the ecological imperative is paramount, this research explores the innovative application of organic pneumatic forms inspired by nature to create architectural structures that dynamically respond to daylight conditions, thereby enhancing energy efficiency and occupant well-being.

The central objective of this study is to bridge the divide between the built environment and the natural world by emulating nature's elegant solutions. To achieve this, a multidisciplinary approach fuses principles from biology, architecture, engineering, and computational design. The research begins with an exhaustive literature review and an indepth analysis of biological systems characterized by organic pneumatic forms found in nature. These pneumatic analogies serve as the foundational inspiration for the subsequent architectural design strategies.

Furthermore, the dissertation features a compelling array of case studies, showcasing the practical application of origami pneumatic forms in real-world architectural contexts. These case studies exemplify innovative design solutions that seamlessly harmonize with the natural environment, reducing energy consumption and elevating the quality of life for occupants.

The synthesis of research findings in this dissertation contributes significantly to the discourse on sustainable architecture and biomimicry. It underscores the potential of origami pneumatic forms as a groundbreaking paradigm for daylight-responsive architectural design. Beyond theoretical advancements, this work offers tangible opportunities to redefine how we conceptualize, design, and inhabit our built surroundings. In conclusion, the dissertation illuminates the transformative power of biomimicry and origami pneumatic forms in reshaping the future of architecture.

List of Figures

Figure 1 Venus’s flower Basket sponge sits in an underwater environment with strong water currents and its lattice like exoskeleton and round shape help disperse those stresses on the organism.

Figure

(Bottom

Figure

1. Introduction

1.1

Background and Context

In contemporary architecture, sustainability and energy efficiency have become paramount concerns. The integration of natural daylight into architectural design is a wellestablished strategy to reduce energy consumption and improve the indoor environment. However, traditional static design approaches often fall short in fully harnessing the potential of daylight. Nature, on the other hand, offers a plethora of examples where organisms and structures dynamically adapt to changing light conditions for survival and well-being. These biological models inspire the concept of biomimetic design in architecture.

Biomimetic architecture seeks to emulate nature's adaptive strategies in the built environment. One promising avenue is the incorporation of origami pneumatic systems, which can respond to varying levels of daylight by altering the building's form and permeability. This dissertation aims to explore how biomimetic principles, coupled with origami pneumatic systems, can revolutionize the design of daylight-responsive architecture, making buildings more sustainable, energy-efficient, and user-friendly.

1.2 Aim of study

The aim of this dissertation is to comprehensively explore the intersection of biomimicry, daylight-responsive architectural design, and origami pneumatic systems, with a focus on achieving innovative and sustainable form generation in built environments and developing a daylight-responsive pneumatic system with the help of origami and biomimetic design.

1.3 Research Objectives

• To conduct a comprehensive review of existing literature on biomimetic design principles, daylight-responsive architecture, and origami pneumatic systems to establish a solid theoretical foundation for the research.

• To identify and analyze specific biological models and natural systems that exhibit daylight-responsive behaviours, focusing on organisms and structures that can serve as inspirational models for architectural design.

• To design, simulate, and develop origami pneumatic systems capable of dynamically responding to changing daylight conditions while integrating biomimetic principles and to summarize the key findings, contributions, and limitations of the research and suggest directions for future studies and advancements in the field of origami, pneumatic, biomimetic architecture and daylight-responsive design.

1.4 Methodology

1.5 Scope and Limitations of the research

Scope:

The scope of this dissertation is focused on the exploration and integration of biomimetic principles and origami pneumatic systems in architectural design, primarily for daylight-responsive applications. It includes theoretical research, simulation and modelling work, prototyping, case studies, and practical considerations related to sustainability and user experience.

Limitations:

• The study's focus is on daylight responsiveness, and while it may touch on broader aspects of biomimicry, it remains primarily architecture-centric.

• Due to resource constraints, the prototyping phase may not encompass a wide range of building types or locations.

• The implementation of the findings in real-world projects may face regulatory and structural limitations.

• The study does not explore all possible biomimetic inspirations but instead focuses on those relevant to daylight-responsive design.

2. Biomimetic Analogies in Nature

2.1 Introduction to Biomimicry

Biomimicry, also known as biomimetic design, bionic design, bio-inspirations, and biognosis, encompasses a range of scientific terms that revolve around the concept of adapting natural systems and principles to innovate industrial products. The idea of biomimicry took shape in the early 1950s with the goal of enhancing human capabilities through the development of tools and technologies inspired by nature. (Benyus, 1998)

In the field of architecture, the terms biomimicry and biomorphism have been coined to describe a modern architectural style that frequently draws inspiration from nature. This style not only utilizes nature as a source of unconventional forms but also incorporates symbolic and metaphoric concepts. For instance, architects like Le Corbusier extensively incorporated natural forms into their designs to convey deeper symbolic meanings. This differentiation serves to emphasize that biomimicry goes beyond mere aesthetics, requiring a functional revolution to bring about transformative solutions, in contrast to biomorphism.

Approaches to biomimicry in the design process typically fall into two categories: firstly, identifying a human need or design problem and seeking solutions by examining how other organisms or ecosystems address similar challenges, referred to as "design looking to biology." Secondly, identifying specific characteristics, behaviors, or functions in organisms or ecosystems and applying these insights to human designs, known as "biology influencing design." (Khoshtinat, 2015)

One of the earliest instances of biomimicry can be traced back to the study of birds, which eventually led to the development of human flight technology The concept of sustainable development is evolving to a level where buildings are conceived as integral parts of the natural environment, supporting and harmonizing with life-sustaining ecosystems. Nature has long been a source of abundant ideas and inspiration for architects in their quest to create sustainable and environmentally friendly architecture. (Khoshtinat, 2015)

Figure 1 Venus’s flower Basket sponge sits in an underwater environment with strong water currents and its lattice like exoskeleton and round shape help disperse those stresses on the organism.

Figure 2 (Bottom left) Architect Norman Foster inspired by this Venus flower designed Gherkin tower

2.2 Biomimetic Taxonomy

The concept of biomimicry also referred to as biomimetics, gained a structured framework through the work of Janine Benyus and her book "Biomimicry: Innovation Inspired by Nature" in 1997 (Benyus, 1998) This taxonomy organizes biological inspirations into a systematic approach. The fundamental idea behind biomimicry is that the genius of nature has already solved many of the problems we face as humans. We, as a relatively recent presence on Earth, acknowledge that life has devised well-adapted solutions that have endured the test of time, all within the constraints of finite resources. Animals, plants, and microbes are truly exceptional engineers. They have filtered what works, what doesn't, what is appropriate, and what endures here on Earth.

In architecture, we borrow from nature's biological recipes by translating morphogenetic principles into three-dimensional prototypes. These prototypes serve as tools to explore various design layers such as skin, structure, and spatial elements in a more efficient manner. Essentially, we seek to emulate the material properties of organic systems using synthetic materials to perform similar functions, such as shielding, cooling, heating, or purging within architectural contexts. In physically and computationally simulated models, the transformations of architectural forms reflect the parallel narrative of evolution in organic systems, driven by functional requirements and situational contexts. Biomimicry, or biomimetics, is like consulting with experienced mentors from the natural world, allowing us to follow in the footsteps of those who have mastered sustainable solutions.

Biomimicry and biomimetics are closely related terms often used interchangeably, with a primary focus on learning from nature in a digital context. These approaches are primarily concerned with functionality and solutions, not necessarily the representational modelling of natural forms often seen in biomorphism. To clarify, biomimetic methodology interprets inherent living patterns into numerical patterns, which then dictate generative formalization in design. In contrast, biomorphism tends to be more aesthetic in nature, involving artistic imitation of natural structures, sometimes before or without considering functionality.

Within the realm of biomimetic practice, there is a significant movement among "green" or "zero-energy" architects who prioritize energy efficiency in building design. Many of these architects rely on building operation systems to achieve point-based certificates and meet standards such as LEED. However, architect Kiel Moe challenges these positions by arguing that architectural buildings are non-isolated thermodynamic systems. These systems have non-linear dynamics that don't align with a simple equilibrium of forces. Taking a functional perspective, when forces are reduced solely to utility and use, the richness and inherent power of feedback and recurrence are lost. This flattens the vitality of design and overlooks its metabolic intricacies. (Moe, 2014) (Phan, 2023)

Figure 3 Biomimicry Taxonomy

Neri Oxman, an architect with a unique approach, offers a tangible response to the idea of harnessing natural forces in the form-finding process. Her work involves the integration of natural data, such as data from skull tissues, mineralization, lighting characteristics, orientation, and the pain profiles of Carpal Tunnel Syndrome patients, into synthetic materials to facilitate digital fabrication. (Oxman, Carpal Skin, Wrist Splint | by Neri Oxman, 2010)

Her work has yielded a range of material properties, including elasticity, sponginess, permeability, and dissolvability, tailored to specific functions. For example, her project "Beast" represents a synthetic creation that mimics organic qualities through the integration of physical parameters and digital form-generation processes. It takes the form of a singular, unbroken surface, serving dual roles as both a structural component and an outer skin. This surface undergoes local modulation to provide structural support and cater to bodily needs. It achieves this by adjusting its thickness, pattern density, stiffness, flexibility, and translucency in response to various factors, including load, curvature, and areas where there's pressure on the skin. (Oxman, Beast, Prototype for a Chaise Lounge | by Neri Oxman, 2008)

Figure 4 The Carpal Skin’s Pattern Designed by Neri Oxman

Figure 5 Beast, Prototype for a Chaise Lounge Designed by Neri Oxman

2.3 From Plant Organs to Architectural Elements

Light, often considered the source of life, plays a pivotal role in the evolutionary process. It aids in the accumulation and distribution of organic matter, shaping forms and enabling various functions, including sustenance. Over generations, organisms adapt their forms in response to changes in light availability, a key factor in their survival. Long ago, light brought energy to the earliest ecosystems through photosynthesis. Therefore, it is logical to seek inspiration from the plant kingdom, as the sunlight requirements of autotrophic plants offer valuable principles for addressing daylighting challenges in architecture. An essential commonality between plants and architecture is their inherent immobility, which subjects them to site-specific exposure to environmental fluctuations, necessitating morphological adaptations. By closely examining the natural models of lighting found in leaf epidermis and plant trichomes, this research combines, modifies, and interprets their principles for application in architectural design.

Leaf surface structures, in direct contact with the environment, play a critical role in the photosynthetic process. Plants native to lower-light habitats tend to have larger leaves. In shade leaves, a greater number of spherical subsidiary cells develop to maximize surface area. These spherical cells on the leaf epidermis form leaf hairs or "trichomes," which enhance light capture and distribution. In architectural terms, this suggests that the outermost layer of façades can be enlarged and transformed into multiple spherical shapes. When combined with translucency variations in architecture, these undulating façades would optimize the opening area while permitting diffused daylight into the interior. (Phan, 2023)

In essence, the study of these natural models offers intriguing possibilities for architects to harness and manipulate light in innovative ways, both on the exterior and interior of buildings, contributing to more efficient and sustainable architectural designs.

Figure 6, Spherical and transparent trichomes on the leaf epidermis

Certain leaves, with their unique structures, offer insights into improving thermal resistance in double-skin facades without compromising daylighting. While increasing the thickness of the air cavity in double skin facades enhances insulation, plants have evolved their own way of enhancing boundary layers through the development and arrangement of trichomes, often referred to as "hairs" ("Factors Affecting Rates of Transpiration," 2020). Despite the existence of more than twenty different types of trichome variations, they all manage to maintain sufficient photosynthesis for the leaf surface beneath the boundary layer. Typically taking on spherical shapes and composed of translucent materials, these trichomes form tiny bubbles (Armstrong, 2017). These hydraulically inflated trichomes, which come in various sizes, can create an air buffer zone without obstructing the necessary sunlight from reaching the chlorophyll-rich area beneath them.

In the natural world, plants rely on their hydraulic mechanisms because nearly 90% of their organic volume consists of water. Leaves are saturated with water, and they have evolved to optimize their use of it. In contrast, architectural spaces are filled with air, which behaves differently from water. Air is lighter and highly compressible, making it safer and more practical to work with in construction. This opens up the potential for developing adaptive systems that can coexist with people without causing harm or generating excessive waste. Therefore, this thesis explores the translation and application of plant principles to architecture, focusing on pneumatic mechanisms.

The concept of varying spherical geometries using hydraulic pressure, inspired by trichomes, holds promise for designing architectural envelopes. If architectural forms can dynamically adjust their volume and translucency, mirroring the behavior of trichomes, they could evolve into organic and multifunctional structures capable of responding to fluctuations in daylight while maintaining thermal performance. It is undeniable that architectural designs featuring responsive inflated surfaces have the potential to replace traditional double-skin facades and become increasingly prevalent in biomimetic designs focused on optimizing daylighting. (Phan, 2023)

Figure 7 Plant Trichomes

2.4 Case Study Al Bahar Towers

2.4.1 Concept

The project's inspiration draws from the traditional Islamic element known as the "Mashrabiya" and its intricate patterns. It seeks to make a unique statement with two circular towers enveloped by a structure reminiscent of a honeycomb, complete with an automated and dynamic solar screen. The "Mashrabiya" is a lattice screen made of wood that is a hallmark of traditional Islamic architecture, serving the purpose of ensuring privacy and controlling the environment, including aspects such as natural ventilation, solar management, and minimizing glare. The project spans an area of 56,000 square meters, primarily intended for office usage (Attia, 2017)

2.4.2

The envelope

The pair of circular towers are equipped with sealed glass curtain walls formed by unitized panels. These panels measure 4200 mm in height and vary in width between 900–120 mm, creating a viewing area that spans 3100 mm from floor to ceiling. Seams or gaps between the curtain wall and the dynamic shading system enable them to react independently. The dynamic shading system consists of triangular units reminiscent of origami umbrellas. These units can adjust their angles to block direct sunlight. Each shading device, referred to as Mashrabiya, extends 2.8 m from the building and includes stainless steel frames, aluminium dynamic frames, and fiberglass mesh infill. The folding mechanism transforms the shading screen from a continuous veil into a lattice pattern. These shading devices feature extended polytetrafluoroethylene (PTFE) panels, allowing for visibility when they are closed. In each tower, there are 1049 Mashrabiya shading devices, each with an approximate weight of 1.5 tonnes. The complex shape of the building necessitates 22 different geometries for the Mashrabiya, which presents challenges in terms of manufacturing and assembly. (Attia, 2017)

Figure 8, Al Bahar Tower

Figure 9 Kinetic Facade in Al Bahar tower

2.4.3

Automation and adaptations

The shading system operates with computer-controlled precision to adapt to optimal solar and lighting conditions. The Mashrabiya shading devices are organized into distinct sectors and are managed through sun-tracking software, which adjusts their opening and closing in response to the sun's position. Each shading unit is comprised of stretched PTFE panels and is actuated by a linear mechanism, opening and closing daily to shield against direct sunlight. In cases of overcast skies or strong winds, the building's sensors send signals to open all units. The control of these 1049 Mashrabiya devices is overseen through a central Building Management System (BMS), enabling both individual and group-level management. Siemens technology is harnessed to automate the system's sun-tracking path, which is updated every 15 minutes based on light and wind data. Weather-related events can override the automated program. Power and data transmission take place through the strut sleeves.

Figure 10 Formation of Origami kinetic facade of Al Bahar towers

Figure 11 Functioning of Origami kinetic facade

3.Pneumatic Analogies in Nature

3.1 Introduction to pneumatic systems

The idea of pneumatic architecture emerged during the 1960s, driven by the desire to develop expansive, air-supported structures. This innovative approach allowed for the construction of lightweight edifices with remarkably vast spans, as well as temporary structures that could be rapidly inflated or deflated. An illustrative example of this technology in action is the Water Cube used for the Beijing Olympic Games.

In contemporary pneumatic architecture, the focus lies in creating designs that are interactive and attuned to the physical surroundings. Pneumatic elements are meticulously crafted to adjust to variables such as sunlight, temperature, humidity, and airflow, ensuring a consistent indoor environment. As technology advances, human engagement with constructed spaces becomes more attainable. Elements that react to human actions promote communication and flexibility, driving the exploration of pneumatic architectural features such as adaptable building exteriors and responsive facades, ultimately enhancing the connections between people and their constructed environments. (Lu, Park, Liu, JI, & Tong, 2019)

Pneumatic structures are sometimes referred to as air-inflated and air-supported structures. The air-stabilized structure is the more pertinent to architectural applications of the two main categories of pneumatic structure: air-controlled and air-stabilized.

Air - Supported Structures: A leak-proof seal is created by one or more layers of continuous flexible membranes that are attached to the ground or to a wall. This type of structure is supported by air. The continuous flow of air then inflates and pressurizes this airtight structure. An air-supported facility has a lifespan of 20 to 25 years on average.

Air - Inflated Structures:

Advanced structures called air cell inflatables are comprised of two layers of material with fabric formers positioned perpendicularly in between. They can be self-supported and selferected using only an air fan; no foundation, hardware, or guy wires are required. Building air's interior volume maintains atmospheric pressure.

Figure 12 Beijing National Aquatics Centre

3.2 Pneumatic Organic Analogies - Generating A Hypothesis

Air is a ubiquitous presence within organic life, permeating cellular layers to facilitate continuous circulation for the transportation of essential resources and the removal of waste from living organisms. In the realm of architecture, the pervasive and inconspicuous exchange of air aligns with the principles of thermal dynamics. Here, architectural structures are perceived as open thermal boundaries that consistently strive to exchange air with their surroundings, as discussed by Moe in 2014. Within numerous biomimetic interpretations, both in theory and practice, architectural designs utilizing air have progressively evolved to become more adaptable, versatile, and flexible. (Phan, 2023)

At a more advanced stage of organic development or evolution, air ceases to be merely a basic chemical resource and instead becomes an integral force. This force is evident in various observable species in the organic world, such as diving-bell spiders and spittlebugs. Among these, the diving-bell spider stands out as the sole known spider species that predominantly resides underwater throughout its life cycle. This spider employs its web to collect air from the surface and transport it to its submerged dwelling, where it forms a distinctive air-filled diving bell, as detailed by Yong in 2011. The spider makes numerous trips between the water's surface and its habitat to replenish the bell with fresh air. This integrated mechanism provides sufficient oxygen to support all of the spider's underwater activities, including swimming, hunting prey, feeding, mating, and caring for its offspring. Similarly, spittlebugs employ air foam as a protective shelter during their larval stage. The larvae continuously release sticky fluid bubbles around themselves to deter predators, fend off infectious diseases, and shield themselves from ultraviolet radiation, as discussed by Gorman in 2019. (Phan, 2023)

Evidently, these species not only rely on air for its fundamental oxygen content but also harness pneumatic functions in diverse ways. In human history, dating back to around 5500 BC, the earliest instances of utilizing air involved harnessing it as a propulsive force for sailing. This practice was employed to move both sea boats and land vehicles, aiding ancient civilizations in the lifting and transportation of goods, as described by Bergman in 2019. (Phan, 2023)

Figure 13 (Bottom Left) A diving-bell spider fuels air into a silk bubble to survive underwater.

Figure 14 (Bottom) Spittlebugs hide inside a structurally stable fortress made from numerous bubbles bundled together.

3.3 Case study on pneumatic structure - Water Cube

3.3.1

Concept and Description

PTW Architecture Company and ARUP construction engineers in Australia collaborated with China Enterprise Confederation, under the leadership of Chinese construction engineering company CSCEC, to secure the world's most significant contract, the "Beijing National Aquatic Centre for the Olympic Games." The team embarked on a quest to discover a unique design concept, which eventually materialized as "soap bubbles." After four months of relentless effort, the Water Cube design was selected from a pool of 10 international proposals through online voting in July 2003. Following the conclusion of the Olympic Games, the facility was transformed into a recreational center accessible to the general public.

Upon discovering that the winning design would be situated in close proximity to the Olympic Stadium, the iconic and gracefully curved 'bird's nest' structure, Arup drew inspiration and promptly determined that the swimming center should take the form of a contrasting blue rectangular structure. The Olympic criteria necessitated the inclusion of a 50meter competition pool, a 33-meter diving pool, and a 50-meter warm-up pool. Additionally, the primary pool area was designed to accommodate 17,000 spectators during the games, with plans to later reduce the seating capacity to 7,000 while incorporating additional amenities to ensure the Center's long-term sustainability and legacy. (Kassem & Azm, 2017)

3.3.2 Smart material - Using ETFE in external skin)

The team opted for ETFE as the material of choice to create see-through cushions for the exterior of the building. ETFE exhibits remarkable strength and durability, capable of enduring the impact of ultraviolet light and air pollution. In comparison to glass, ETFE stood out as a superior option due to its excellent acoustic and insulating qualities. Additionally, its lightweight characteristics eliminated the need for an extra support structure to uphold the outer layer.

Figure 15 Water cube, Beijing

Figure 16 Components of Smart skin of water cube

3.3.3 Using movable ETFE units as a Smart Ceiling

Solar panels are implemented to capture and retain 20% of the solar energy that reaches the structure. This solar energy is harnessed for warming the air in the vicinity of the swimming pools and heating the water, resulting in potential energy savings of up to 30% when compared to other water park facilities. The control of self-generated energy stored between the two layers of ETFE is achieved through the utilization of a series of openings, resembling "vertical cylinders enclosed with circular panels" at their top and bottom. During the winter, these openings remain sealed, while in the summer, they are opened to varying degrees to release heat energy.

3.3.4 Using ETFE as a self-healing material

ETFE material can endure UV radiation, strong winds, and snow, although it is exceptionally thin and can be cut with a knife. The upkeep of this structure differs from traditional building maintenance; for repairing any damaged cushions, simply applying a patch to the punctured area is adequate. The cushions possess a self-healing quality, given their high-pressure state, and any holes or damage will naturally diminish over time.

3.3.5 Functional Features and Benefits:

1. Interactive Movable Ceiling Units:

- Offers flexible space utilization.

- Allows for the incorporation of future smart systems.

2. Natural Lighting:

- Utilizes smart materials in the building's outer skin to regulate the amount of natural sunlight entering.

3. Artificial Lighting System:

- Utilizes motion detectors and monitoring devices to assess lighting levels, movement, and adjust brightness accordingly.

- Controls ceiling panels through computer systems.

4. Natural Ventilation

- Utilizes adaptable smart materials in the building's outer envelope to prevent heat transfer.

- Includes heating circles in the ground and ceiling for added comfort.

5. Artificial Ventilation:

- Manages ventilation through smart systems for optimal air quality.

- Utilizes smart sensors to gather data on internal and external environmental conditions.

Figure 17 Interior of Beijing aquatic center

4. Pneumatic Origami-Inspired Structure

4.1 Introduction to Origami

Origami, an ancient and intricate craft involving the folding of flat paper into sturdy threedimensional shapes, has discovered widespread utility across diverse domains such as engineering, machinery, aviation, and architecture. In the realm of architecture, origami structures are highly regarded for their capacity to deliver stability over extensive areas

For instance, take the Yokohama International Passenger Terminal, a creation by Japan's Foreign Office Architects, which stands as a remarkable example. Its inner roof is comprised of folded diamond-shaped components, and the overall shape of the roof resembles that of a single folded sheet of paper. This origami-inspired design proves instrumental in bearing substantial loads while upholding structural integrity. (Lu, Park, Liu, JI, & Tong, 2019)

Origami structures present the benefit of flexibility and the ability to expand and contract in both space and form. Back in 1961, Spanish architect Pinero E.P. demonstrated the effective application of folding structures in designing mobile theaters. In the aerospace sector, the Miura origami structure, devised by Miura Koryo from the University of Tokyo, introduced an inventive resolution for addressing solar cell expansion challenges. These cases underscore how origami structures effectively achieve adaptability and versatility in both architectural and mechanical contexts.

Figure 19 Yokohama International Passenger terminal

Figure 18 Yokohama International Passenger Terminal

4.2 Functioning of Pneumatic Origami Joints

The Pneumatic Origami Joint has the capability to produce three distinct types of movements: stretching, bending, and combined motion. To attain the desired motion, the design of the 3D printed joints is tailored to undergo precise deformations during the process of inflating and deflating the airtight casing.

4.2.1 Stretching Motion Joint

During the stretching motion, a cardboard strip is repeatedly folded into a zigzag pattern. When the air is withdrawn from the pouch, the cardboard conforms to the folds, causing the end of the airbag to retract. Conversely, when the bag is filled with air, the cardboard elongates. The degree of stretching in this motion is determined by the distance between the neighboring folds (Lu, Park, Liu, JI, & Tong, 2019)

4.2.2 Bending Motion Joint

The bending action of the joint is directly linked to the stretching movement. As the origami structure undergoes stretching and is partially folded, it provides stability to the base of the structure. Internally, the origami structure takes on the appearance of a truss structure, with each origami unit resembling triangular prisms. When these units are compressed, the volume decreases as the angle between adjacent triangular prisms narrows, leading to a bending motion.

Figure 20 Functioning of pneumatic origami joints

Figure 21 Stretching Motion Joint

Figure 22 Bending Motion Joint

4.2.3 Compound Motion Joint

The compound motion joint is mainly rooted in bending, incorporating bending in two dimensions. It alters the unit's form from a triangular prism to a quadrangular prism and shifts the point of intersection from an edge to a vertex. This arrangement enables the joint to not only compress vertically but also flex horizontally, producing a rotational motion when these two motions coincide.

4.2.4 Fabrication

Additive Manufacture Technology

The joints are produced using Additive Manufacturing (3D printing) technology due to several advantages. Firstly, 3D printing allows for high customization, accommodating variations in joint placement, movement, bending amplitude, and intensity within the building. This technology can adapt well to these diverse requirements. Secondly, rigid 3D-printed components enhance joint strength, which is crucial since each joint experiences stress and needs to support the entire structure. Pneumatic joints, in particular, must withstand atmospheric pressure under vacuum conditions, further emphasizing the need for strength. Lastly, 3D printing simplifies production processes, increasing efficiency. It utilizes a single material, while traditional joints made from various materials can complicate movements and reduce usability if not designed properly. However, using additive manufacturing technology for joints presents challenges, notably the need to transform rigid materials like PLA or ABS into flexible materials during the integrated printing process. (Lu, Park, Liu, JI, & Tong, 2019)

Airbag

A variety of materials for the sealed airbag have undergone testing, including common plastics such as polyethylene, polypropylene, polyester, and nylon. The chosen material must be able to withstand barometric pressure and maintain its shape when stretched. In line with these requirements, thermoplastic polyethylene (PE) is chosen as the airbag material. Maintaining airtight integrity is of paramount importance in pneumatic systems. Given the limitations of heat seals in terms of size, adjustments are made to the joints within the permissible dimensions (Lu, Park, Liu, JI, & Tong, 2019)

Figure 23 Compound Motion Joint

5. Materiality: Organic and Synthetic Convergence

5.1 Silicone Rubber: Life-casting building materials

The materials used in making pneumatic components, whether organic or inorganic, should mimic the elasticity and consistency found in biological tissues to enhance the interaction between humans and machines. Traditional rigid materials like metal, glass, and acrylic are being replaced by soft materials in the fabrication of mechanical actuators, allowing for more biomimetic designs that better align with the human body. This shift enables a safer interaction between users and machines by reducing physical separation due to machinery hazards.

Architects and designers have been actively exploring more "natural" materials in their projects. For example, back in 2004, a 40-foot tower composed of over 10,000 biodegradable bricks called Hy-Fi was showcased in MoMA's PS1 courtyard. This innovative structure, designed by David Benjamin and Ecovative, involved the cultivation of mushroom bricks using mycelium molds as an environmentally friendly alternative to traditional building materials. Although Hy-Fi endured three years of degradation, Benjamin was optimistic that this new material would increasingly find its way into the construction industry in the near future.

In 2015, Benjamin collaborated with Rockefeller University's Stem Cell Biology and Molecular Embryology lab to create the Amphibious Envelope. This architectural concept integrated a miniature frog habitat into a double-skin facade, serving to purify the interior atmosphere. Benjamin's approach involves a direct engagement with living materials, utilizing compounds from living organisms to replicate conventional building supplies or introducing ecosystems onto building facades. His methodology aligns with the principles of sustainable architecture, taking into account the finite resources available on Earth. However, the use of living materials also raises questions about the availability of labor for long-term maintenance of such structures.

Silicone stands out as a distinctive material that possesses three key attributes: softness, elasticity, and translucency, making it an excellent choice for biomimetic, pneumatic, and daylighting design. Furthermore, being classified as an elastomer, it has the capacity to withstand deformation of up to 1000% of its original dimensions, a characteristic referred to as its "elongation at break". (Phan, 2023)

Figure 24 Living's Hi-fi Installation

ETFE (Ethylene Tetrafluoroethylene) is a remarkable material that has revolutionized traditional construction methods by enabling the creation of lightweight and flexible structures. Buildings using ETFE sheeting can provide excellent natural lighting like traditional glazing systems but with only 1% of the weight of glass. ETFE has found successful applications in projects worldwide, including office buildings and mixed-use towers. Recognizing the advantages of ETFE as a member of the rubber family, the design exploration in this project pushes the boundaries further toward a softer and more flexible material within the same family – silicone. Silicone emulates the physical properties of organic tissues, making it ideal for addressing daylighting requirements. There are four key reasons why silicone is considered more suitable for this project and emerging responsive building facades:

1. Dynamic Elasticity: ETFE's lower elasticity restricts pneumatic units to fixed frames. With provisional air pressure, ETFE bubbles cannot change their expansion unless there is a modification in the grid pattern. In contrast, silicone panels can dynamically expand under the same air pressure by varying thickness and incorporating different hardness values.

2. Flexibility After Deflation: Silicone can return to its normal state after deflation, while an ETFE surface becomes shaggy and wrinkled. This inherent flexibility of silicone allows for the possibility of a kinetic system. ETFE panels must remain inflated at all times, necessitating that the supporting frames anchoring them move in tandem if the panels need to change position.

3. Independent Design and Grid Systems: In a provisional grid system, the inflation behavior of silicone units can be independently designed through casting and molding. In contrast, ETFE panels require alterations to the support structure to meet daylighting requirements in an existing building. This reduces material complexity, particularly in cramped urban locations like Toronto, where retrofitting existing structures is common.

4. Self-Cleaning Ability: Pneumatic units made of silicone possess self-cleaning capabilities. They can automatically remove dirt and snow thanks to regular movements associated with inflating and deflating.

Figure 25 ETFE Cushions on the Facade of the Water Cube

5.2 ETFE film sheet under temperature change

5.2.1 Introduction

Researchers have been closely examining the visco-elastic properties of ETFE (Ethylene Tetrafluoroethylene) film due to its unique characteristics. ETFE, as a high polymer material, exhibits a linear expansion coefficient that is ten times greater than materials like steel, making it susceptible to expansion and contraction with temperature variations. Consequently, in the context of designing and constructing ETFE film membrane structures, extensive research has been conducted to better understand its visco-elastic behavior.

In the realm of studying the viscosity of ETFE film, various investigations, including those conducted by the authors, have been carried out by researchers such as Moriyama, Kawabata, Jeong, Wu, Galliot, Luchsinger, Li, Wu, and others. These studies have considered different aspects, including viscosity, temperature changes, and the introduction of the constitutive equation of Finite Element Method (FEM). However, none of these studies have comprehensively considered all these factors together.

In their research, the authors conducted biaxial tension assessments and shearing experiments on ETFE film under constant temperature conditions, adhering to the MSAJ Standards. These assessments encompassed biaxial tension trials involving five distinct stress ratios, enabling them to establish the connection between equivalent stress and equivalent plastic strain. Irrespective of the stress ratios applied, the plots illustrating equivalent stress and equivalent plastic strain remained consistent. This affirmed the effectiveness of the suggested elastic-plastic constitutive equation in describing aspects like the yield stress, stress following material breakdown, and the strain relationship. Moreover, through pressurization trials on square-plan membrane structures, it was evident that the proposed elastic-plastic constitutive equation aptly represented their behavior.

Furthermore, the authors expanded the suggested nonlinear viscoelastic constitutive equation from uniaxial tension to biaxial tension, as mentioned in prior studies. This constitutive equation, developed incrementally using the Finite Element Method, considers factors such as time passage, alterations in stress, and temperature disparities. It's essential to recognize that while the Time-Temperature Superposition principle can accommodate the impact of temperature variations on the viscosity aspect, it doesn't address the expansion and contraction resulting from temperature fluctuations

Expanding on this groundwork, this paper takes the incremental format of the nonlinear viscoelastic constitutive equation, initially designed for biaxial tension scenarios, and broadens its scope to account for the consequences of temperature-induced expansion and contraction. The paper confirms the effectiveness of this extended constitutive equation in addressing the factors of time passage, fluctuations in stress, and shifts in temperature (Yoshino & Kato, 2016)

In particular, the aims are as follows:

1) Broaden the incremental constitutive equation for the biaxial tension domain, as introduced in a prior publication, to encompass expansion and contraction caused by temperature shifts.

2) Perform uniaxial creep experiments in situations where temperature varies and report the outcomes. These results, emphasizing the expansion and contraction arising from temperature fluctuations, will be employed to derive the essential constants needed for the constitutive equation.

3) Apply the suggested constitutive model and the determined constants to replicate uniaxial creep trials conducted under conditions involving temperature variations.

5.2.2 Conclusion

“In this study, we expanded the incremental nonlinear viscoelastic constitutive equation originally designed for the biaxial tension field to incorporate the part related to thermal expansion caused by temperature fluctuations. Through thermomechanical analysis, we determined the coefficient of linear expansion as a characteristic of thermal expansion.” (Yoshino & Kato, 2016)

“Furthermore, we conducted uniaxial creep tests under two conditions: one at a fixed temperature and another with temperature variations. These tests helped us confirm that uniaxial creep behavior is indeed influenced by temperature changes. Additionally, we used the proposed constitutive equation to simulate uniaxial creep tests under varying temperatures. The simulation results demonstrated that creep behavior can be accurately described by the proposed equation.” (Yoshino & Kato, 2016)

“These findings validate that the constitutive law we developed can effectively account for elapsed time, stress variations, and temperature fluctuations. To further enhance the comprehensiveness of our research, additional comparative studies should be conducted. For instance, we can investigate biaxial creep behavior accompanied by temperature variations at various stress ratios and explore other conditions not covered in the current study.” (Yoshino & Kato, 2016)

6.Biomimetic Approach to Daylight-Responsive Design

6.1.

Translating Biological Analogies to Architectural Design

Behavior of Plant trichomes-

The surface of plant trichomes behaves like a convex surface it is known for its ability to converge or focus light rays that pass through it which leads to heating-up of the central core of the plant trichomes Trichomes are organic and multifunctional structures capable of responding to fluctuations in daylight while maintaining the thermal performance.

It is very evident that architectural designs featuring responsive inflated surfaces have the potential to replace traditional double-skin facades and become increasingly successful in biomimetic designs focused on optimizing daylighting.

Behavior of diving bell spider-

The diving bell spider creates air chambers with its silk, which serve as a means for breathing. These air bubbles function like gills, extracting dissolved oxygen from the water and releasing carbon dioxide.

Numerous biomimetic interpretations like these can help architectural designs to utilize air and progressively evolve into more adaptable, versatile, and flexible structures.

Figure 26 Behavior of Plant trichomes

Figure 27 Functioning of Diving bell spider

6.2. Presentation of Design Outcomes

Figure 28 Source: Author

Figure 29 Source: Author

Figure 30 Source: Author

Source: Author

Figure 31 Grasshopper Code

6.3. Discussion of Design Successes and Challenges

6.3.1 Design

Successes:

• Adaptive Facade: The bio-inspired origami pneumatic facade can adapt to environmental conditions such as temperature. This adaptability can enhance energy efficiency by regulating the building's interior temperature.

• Energy Efficiency: The folding and unfolding of the origami-inspired design can help control the amount heat entering the building by inflation or deflation of origami pneumatic structure

• Aesthetics: Origami-inspired designs can offer unique and aesthetically pleasing architectural features. The folding and unfolding patterns can be visually engaging and contribute to the overall appearance of the building.

• Customization: Origami-based designs allow for a high degree of customization. The design can be tailored to the specific needs and aesthetics of the building or space.

6.3.2 Design Challenges:

• Material Selection: Choosing the right materials for the origami pneumatic structure can be challenging. The material needs to be lightweight, durable, and capable of withstanding environmental conditions. Additionally, the materials must allow for folding and unfolding without deformation.

• Cost: The development and installation of a bio-inspired origami pneumatic facade can be costly. The materials, technology, and engineering involved may require a significant investment.

• Maintenance: Regular maintenance is essential to keep the system in good working condition. The ETFE may be subjected to wear and tear, which can affect the long-term reliability.

• Regulatory and Safety Compliance: Meeting building codes and safety standards can be challenging, especially when working with innovative architectural designs. Ensuring that the origami facade complies with local regulations and safety standards is crucial.

Conclusions

In conclusion, the development of a bioinspired daylight-responsive origami pneumatic facade represents a remarkable fusion of nature-inspired design and architecture. This innovative architectural solution draws inspiration from the intricacies of biological systems to create a dynamic and adaptable building envelope. By mimicking how plant trichomes respond to light, this facade not only enhances energy efficiency but also adds a touch of aesthetic elegance to modern architecture.

The incorporation of origami principles allows for flexibility and transformation, ensuring that the building's exterior can adapt to changing environmental conditions. The pneumatic origami facade promotes sustainability and human comfort.

In an era where sustainability and energy efficiency are paramount, this bioinspired daylight-responsive origami pneumatic facade offers a forward-thinking approach to biomimetic design. It exemplifies the potential of biomimicry to inspire innovative solutions to world of architecture. As we continue to explore the harmonious relationship between nature and technology, this bioinspired facade serves as a beacon of creativity and a testament to the endless possibilities that lie ahead in the realm of sustainable, adaptable, and aesthetically captivating design.

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