How Bio-Based Building Materials Are Transforming Architecture

A colorful grid of bio-based tiles rests atop a black surface. Created as sustainable alternatives to products ranging from acoustic cladding to frosted glass, the tiles derive from eggshells, expired lentils, and other green waste. These palm-sized squares, despite their origins in food scraps, invite tactile investigation. The same lure emanates from a neighboring rug swatch woven from Abaca fiber; a masonry-like block composed of sugarcane; and textile strips made from apple pomace. This enticing display accompanied “Material Time,” a day-long symposium at the Harvard Graduate School of Design held in mid-April that explored our emerging relationship with bio-based materials.

Amelia Gan (MDes ’23) organized “Material Time” in her capacity as the GSD’s 2023–24 Irving Innovation Fellow. She collaborated with Ann Whiteside, Assistant Dean for Information Studies at the GSD, and Margot Nishimura, Dean of Libraries at Rhode Island School of Design (RISD), who had previously cofounded Material Order , a knowledge-sharing resource for design materials collections in academic libraries. Conceptualizing the symposium, the three organizers identified practitioners, researchers, and educators at various stages in their careers whose work touches on design scales from microbes to building systems to outer space. The resulting discussion foregrounded the urgent need for transformations in how we think about and interact with the materials that comprise our built environment.

Concrete, aluminum, and steel rank among the most prevalent materials in contemporary construction. They are also quite costly in terms of their environmental toll. Developed from dwindling non-renewable resources, such conventional engineered building products inflict widespread ecological harm, from their extractive, carbon-intensive manufacturing processes to their final disposal in landfills where they languish, leaching pollutants into the earth. Bio-based counterparts offer a potential alternative to these destructive materials.

In her introductory remarks to the symposium, Gan announced that the time has come for design professionals to “critically rethink our material choices.” Indeed, “the prevailing ethos, which celebrates idealized, unchanging form, finds itself at a crossroads challenged by materials sensitive to environmental changes,” Gan continued. “How do we reconsider the way we represent and construct our environment?” Fortunately, bio-based materials offer a compelling lens through which to reexamine construction techniques as well as expectations about how materials look and what they can do.

Consider bacterial biocement, as fabricated by Laura Maria Gonzalez, founder of Microbi Design and former researcher at the Massachusetts Institute of Technology’s Media Lab. Utilizing computational design and 3D printing, Gonzalez creates sculptural molds infused with sand and bacteria. As the microbes are fed, the mixture hardens into solid forms that, with continued nourishment, become stronger over time. If fractures occur, these living bricks heal themselves through microbial growth. They may even be programmed to signal, through a change in color, the presence of environmental toxins such as lead or arsenic. For Gonzalez, bacterial biocement promises more than a sustainable replacement for more carbon-intensive materials; it presents an opportunity to think about “how we integrate these organisms as living systems to engage more deeply with our environment.”

Paul Lewis, principal of LTL Architects and Professor at Princeton University School of Architecture, emphasized a different behavior we could seek from bio-based materials—that of performing multiple functions. As opposed to aggregated thin, lightweight, single-use products that comprise the typical modernist building section—structure, insulation, waterproofing, and so on—Lewis has experimented with using straw in bale-like configurations that act simultaneously as insulation and load-bearing structure, from which space can be carved. Lewis advocated embracing ideas that are “fundamentally at odds” with the “given values we’ve inherited from modernism,” aligning his explorations with the growing recognition that buildings as constructed throughout the past century have played a significant role in our current ecological predicament. John May, cofounder of MILLIØNS and Associate Professor of Architecture at the GSD, echoed this sentiment as he characterized the term, and the very concept of, “waste” as a vestige of a past industrial capitalist era. Rather, that which has been previously seen as waste should now be embraced as raw materials for other processes.

Underscoring the significance of terminology, Lola Ben-Alon, Assistant Professor and Director of the Natural Materials Lab at Columbia Graduate School of Architecture, Planning, and Preservation (GSAPP), cautioned that “bio-based” materials are not necessarily less extractive or energy intensive than conventional materials. To ascertain environmental impact, she advocated examining a product’s entire life cycle, with a focus on a system’s inputs and outputs. “How are these bio-based materials produced?” Ben-Alon asked. “And where? What are the processes involved in the extraction of these materials? Where are they extracted? And can we pose other means or methods of locally creating these materials?” Such systems thinking—understood as a holistic approach that views component parts in relation to the broader dynamic systems to which they belong—emerged throughout the symposium.

For example, systems thinking came to the fore with Lina Ghotmeh’s presentation, which focused on her design firm’s use of bio-sourced materials. Ghotmeh—currently Kenzo Tange Design Critic in Architecture at the GSD—featured the recently completed Hermès Maroquinerie de Louviers, a leather workshop constructed with locally manufactured low-carbon bricks that showcase the skill of Normandy’s brickmakers. This project is the first industrial building to earn the French E4C2 label, denoting the country’s highest recognized levels of energy efficiency (it is a positive energy building) and operational efficiency (in terms of carbon footprint reduction).

Drawing on concepts resonant with systems thinking, Martin Bechthold, Kumagai Professor of Architectural Technology and Director of the Material Processes and Systems Group (MaP+S) , discussed the iterative processes of science and design, highlighting their similarities and differences, particularly that designers tend to work at a larger scale. And later, Pablo Pérez-Ramos, Assistant Professor of Landscape Architecture at the GSD, expanded the conversation beyond our planet with a consideration of thermodynamics and ways in which these universal laws may help us grapple with conditions of extreme heat in certain landscapes.

Yet another instance of system thinking emerged in the position of Jennifer Bissonnette, Interim Director of RISD’s Nature Lab, who called for “artists and designers to have a certain level of eco literacy.” Design programs, Bissonnette argued, have a responsibility to “turn out people who have a sense of how ecosystems function,” the “cycles, flows, nested systems, development, dynamic balance” that serve as “organizing principles of the natural world.” Likewise, she advocated that scientists be schooled in studio methodology and design thinking to broaden their investigative repertoires. Such pedagogical shifts would go a long way in facilitating the multidisciplinary cooperation—from conceptualization and experimentation through scaling up to real-world manufacturing and application—that bio-based materials necessitate.

Reflecting on “Material Time” a few weeks later, Gan reiterated the need to overcome disciplinary silos. “These conversations shouldn’t happen in a vacuum, yet that often tends to occur,” especially when operating in the complex realm of bio-based materials, which encompasses design, biology, engineering, politics, ecology, sociology, and more. “The challenge is,” Gan continued, “how do you move from a high-level conversation to productive action?” Formulated to further interdisciplinary and intergenerational discussions within the GSD and beyond, “Material Time” offered an exemplary step in the right direction.

 

GSD begins patient isolation hood (PIH) design and fabrication alongside ongoing PPE efforts

Amid ongoing fabrication and delivery of face masks and shields, Harvard Graduate School of Design staff and faculty have added another critical piece of personal protective equipment, or PPE, to their production roster: patient isolation hoods, or PIHs, intended to contain the coronavirus in clinical settings and protect medical professionals. The GSD’s Digital Fabrication Specialist Chris Hansen has collaborated with an array of Harvard and GSD colleagues to design two PIH prototypes, fabricating them on April 13 and delivering them to Massachusetts General Hospital (MGH) on April 14. Hansen and colleagues spent much of April 15 on continued design and prototyping; by the end of this week, the GSD aims to have produced between 20 and 30 PIHs for a trial run in MGH’s intensive care unit. Hansen’s PIH collaborators include the GSD’s Zach Seibold, Lecturer in Architecture; Nathan Phipps, a researcher at Harvard’s Wyss Institute for Biologically Inspired Engineering; Eric Höweler, Associate Professor of Architecture at the GSD; and Saurabh Mhatre, a research associate at the GSD’s Material Processes and Systems Group (MaPS). (Seibold and Mhatre are also each a graduate of the GSD’s Master in Design Studies program.) The cohort’s two PIH prototypes cover a patient’s head and body, with apertures that allow doctors to insert a breathing tube or attach a ventilator as needed, and ample space within the structure to enable physical intervention by medical staff. Hansen describes a design process that started with clinical requirements, followed by conceptual renderings and a gradual weeding-down of these renderings alongside doctor feedback, until producible prototypes emerged. In each design, the hood has two holes for doctors to insert their arms and access the patient, as well as an opening for a breathing tube. Other key design elements include negative air pressure within, intended to suck infectious aerosol particles away from the care-giving doctor; a drape that acts as a closable membrane between patient and plastic hood, with no rigid forms placed on the patient; and a lightweight, disposable overall envelope. Flexibility of use throughout the medical process was a cornerstone of the design process. The Harvard cohort’s design work has been conducted largely via a Slack channel they’ve titled “Full Body Protection MGB,” with a design process that’s spanned much of the past two weeks. They have worked alongside Dr. Samuel Smith, an anesthesiologist at MGH and instructor at Harvard Medical School, in order to apply medical-design guidelines to their process. As Smith observes in Architectural Record, such a marriage of architecture and medicine is fruitful on various—and urgent—levels. “If it doesn’t function well, both ergonomically and practically, it’s not going to be useful to physicians,” Smith says. “Architects need to be more involved with health care innovation and my colleagues need to understand that design matters.” Read more about the GSD’s PIH efforts in Architectural Record.

Martin Bechthold

Martin Bechthold is the Kumagai Professor of Architectural Technology in the GSD’s Department of Architecture and currently serves as the GSD’s Academic Dean as well as the head of the Advanced Studies Programs. Bechthold was the founding Co-Director of the Master in Design Engineering Program and is Affiliate Faculty at the Paulson School of Engineering and Applied Sciences (SEAS) at Harvard. He teaches courses in design and research methods, material systems, and building structures. Recent courses include ‘Towards a New Science of Design?’, ‘Nano, Micro, Macro: BioFabrication’, ‘Faux: Design, Performance and Perception of Fake Materials’ as well as ‘Structural Design II’.

Bechthold received a Diplom-Ingenieur degree in architecture from the Rheinisch-Westfalische Technische Hochschule in Aachen, Germany, and a Doctor of Design Degree from the Graduate School of Design at Harvard University. He is a registered architect in Germany and has practiced in London, Paris, and Hamburg. During this period he was associated with firms such as Skidmore, Owings & Merrill, Santiago Calatrava and von Gerkan, Marg & Partner.

In 2010 Bechthold founded the GSD’s Design Robotics Group and, in 2014, merged it into the Material Processes and Systems (MaP+S) Group , a collaboration of faculty, post-doctoral fellows, research associates, and students that pursues sponsored and other research projects. MaP+S’s current research focuses on low carbon material systems, architectural ceramics, and on understanding the role materials play in our perception of and behavior in buildings. In 2018 Bechthold initiated the creation of the Laboratory for Design Technology as a collaborative platform that connects Harvard Faculty and researchers with forward looking thought leaders from industry.

Bechthold is co-author of ‘Structures’ and ‘Computer-Aided Design and Manufacturing’, as well as the author of ‘Innovative Surface Structures’. His most recent book is ‘Ceramic Material Systems’. Bechthold’s peer reviewed journal papers have been published in widely read journals including Nature Reviews, Advanced Functional Materials, and Energy and Buildings. He holds multiple patents on material innovations.

Terracotta Bricks

Unfamiliar with many of the properties and methods of working with ceramics—armed only with a knowledge of the material research process and a substantial collective design background—the goal of this project was to unite a large-scale architectural agenda with an existing vocabulary of techniques from the ceramics realm. With a focus on light, visual permeability and the use of digital tools to aid in the design process, Celosía Cosída began with the idea that we wanted to create an adaptive, architectural screen with a large number of potential functions and configurations. The idea of modularity quickly came to be another key point of the research as the process of slip casting and creating a series of “molds and multiples” presented itself as the obvious choice for integrating digital fabrication and ceramics.

The hypothesis of the research phase ultimately became that with a single mold, varying only the perforations that allowed light and air to pass through the module, we could create a highly-versatile, visually-elegant screen that incorporated lighting elements and even ways of conditioning a space through radiative heating or evaporative cooling. Though the spatial conditioning was deemed to be an unreasonable endeavor with ceramics at this scale and with the given timeframe of the research, the question of how to do it remains an interesting problem and is explored — though not to any full extent — in this document.

From the beginning of the design process, we were intrigued by the possibilities offered by a cylindrical shape. We wanted to explore the different results that are made possible by the inherent flexibility that rotation offers in relation to creating visual permeability. We experimented with both vertical and horizontal stacking patterns, starting with a simple cylinder and addin curvature as we moved on. Our final component consists of a 90-degree curved pipe, with the dimensions as shown above. Aside from the curved component, our formation required a T-shaped piece, that would connect the end points on the floor and on the ceiling.

Student team

Alexander Jacobson, Josh Schecter, Christina Papadopoulou, Annapurna Akkineni (MDes EE ’16)
Sponsored by ASCER

Ceramic Futures

Martin Bechthold, Professor of Architectural Technology, and Christoph Reinhart, Associate Professor of Architectural Technology, with support and funding from the Spanish Ceramic Tile Manufacturers’ Association (ASCER), have developed a process for making an external shading system of unique, high performance, aesthetically pleasing ceramic tile louvers. The process marries design and performance to create a product system that has the potential to transform building façade cladding and mitigate energy consumption while improving the quality of life for inhabitants.

A student team led by Reinhart developed an early version for a new ‘form suggesting’ algorithm that optimizes the form of an arbitrarily shaped surface intended to be a shading element in consideration of annual heating and cooling loads. A prototype of the algorithm called ‘SHADERADE’ was implemented into the popular Rhinoceros/Grasshopper CAD Environment and was also linked to both the US Department of Energy’s Energy Plus and Radiance state-of-the-art simulation engines. A paper describing SHADERADE will be presented November 2011 in Sydney, Australia at Building Simulation 2011, the world’s premier building performance simulation conference.

After the surface has been transformed into optimized, aesthetically pleasing louver segments, each tile must be isolated and fabricated. Traditionally a custom mold needed to be produced for all individually shaped tiles. That created a high level of waste due to the number of molds that needed to be manufactured as well as the very limited applications for re-use. Additionally, there was a high level of production inefficiency resulting from the labor and time needed to produce the unique tile louvers. Responding to this challenge, another student team led by Bechthold developed a novel production technique for manufacturing the custom tiles using a variable pin mold and a robotically controlled ceramic deposition system. Due to its fluid forming properties, ceramic was considered an ideal material for the louvers. Both teams also chose to work with the widely adopted software platform Rhinoceros and Grasshopper to demonstrate that advanced parametric modeling and fabrication can be achieved through accessible and open interface software.

A sculptural shading screen was developed as a prototypical design experiment. Louvers range from near vertical to horizontal; their twisted and curved shapes make for a formidable fabrication challenge. The team, including doctoral candidate Jonathan King, research associates Anthony Kane and Justin Lavallee, developed a two-pronged approach whereby a variable “pin” mold was used to form a surface onto which a robotically guided extruder deposited ceramic material. The low-cost mold apparatus consists of adjustable vertical pins that can be positioned robotically with the same robotic work cell used to deposit the ceramic material. Software scripts automate the generation of the robotic instructions based on the optimized louver tile surfaces. Scaling the tile surfaces compensates for shrinkage encountered during the drying and firing of the ceramic. The software rotates and positions the louvers for virtual production, then generates the individual robotic code for actuating the pin mold. The ends of the pins replicate the tile surface and a proprietary cam mechanism locks the mold in place.

The robotic ceramic deposition system extrudes clay through a custom nozzle head attached to an ABB robotic arm. The position and path of the nozzle head is precisely controlled. The code needed to run the robot is, again, automatically generated using the team’s custom tools within the design software. The path of the clay extrusion can be precisely calibrated to produce robust tiles. The outer surface of prototypical production tiles was robotically post-processed to achieve a finish compatible with industrial standards. Using the industrial robot, the contours of the deposited, dried clay can be dimensionally rectified to accommodate for shrinkage during firing.

The current prototypical process will be further developed for potential incorporation—in part or as a whole—into low-volume industrial tile production settings. Ongoing work investigates new clay mixtures to produce fluidity with decreased clay water content. Nozzle and deposition methods are also undergoing constant refinements, targeting a finish quality that eliminates post-processing entirely. Finally, the team is looking forward to investigating new tile shapes in order to demonstrate the flexibility and appeal of this new and exciting ceramic fabrication method.

The processes and techniques developed in this project offer a way to reconcile performance and design so that they work together harmoniously to produce building facades that are both formally expressive and environmentally optimized.

For more information on this and other research projects in robotic fabrication, visit the Design Robotics Group .

Core Team Members:
Nathan King (DDes), Shelby Doyle (MArch), Anthony Kane, Jeffrey Niemasz (MArch), Justin Lavallee, Jon Sargent (MArch), Ben Tew, Corey Yurkovich

Special Thanks To:
Ana Martinez Balaguer and Pepe Castellano of ASCER as well as Javier Mira (Instituto de Technologia Ceramica, Castellon, Spain) for their support. Assistance was also provided by Forrest Snyder, Kathy King, and Shawn Panepinto from the Harvard Ceramics Program. Cameron Willard and his team in the GSD Fabrication Lab supported the prototyping efforts and production assistance was provided by GSD students Corey Yurkovich, Ben Tew, Arseni Zaitsev, and Alexander Watchman.

Rendering: Jan Kokol
Video Editing: Carnaven Chiu

Sponsored by ASCER (Spanish Ceramic Tile Association)

Concrete Origami

This project researched parametric design and related fabrication methods for cementitious composite folded plate systems. As a proof of concept an arch was constructed as a prototypical folded plate system. The prototype was pre-fabricated in three segments and then mounted on the timber platform. The span of the arch is 6.6 m, its height is 2m, and the plate thickness is 22 mm.

The prototype investigates a new process for making complex folded plate systems out of cementitious composite materials: systems are subdivided into pre-fabricated units that are poured flat over a simple formwork. The joint lines are left free when adding the cement matrix. The mesh reinforcement continuous through these joints such that the flat system can be folded into its final three-dimensional configuration once the plates are sufficiently cured. The flexible joints are then made rigid by filling them with a high-strength expansion grout that cures rapidly. Once cured the folded system can be lifted up and mounted in its final position, supported by a temporary support that is eventually removed.

A variety of composites were tested as small specimen subject to compression and bending in order to determine the proper material mix for the full-size system. Based on the tests the plate joints were reinforced with a non-woven carbon fiber mesh, and the plates themselves were solely reinforced with 2 inch long synthetic fibers. The material properties of the composite (such as strength and modulus of elasticity) as determined in the tests were used to analyze the arch structurally and simulate stresses and deflections using finite-element analysis. Load tests on the arch will eventually compare the actual deflections under load to the prediction of the computational model.