Natural materials that have evolved in plants and animals often display spectacular mechanical and optical properties. For example, spider silk is as strong as steel and tougher than Kevlar, which is used in bullet-proof vests. Inspired by nature, chemists are now synthesizing materials that mimic the structures and properties of shells, bones, muscle, leaves, feathers, and other natural materials. In this talk, I will discuss our recent discovery of a new type of coloured glass that is a mimic of beetle shells. [emphasis mine] These new materials have intriguing optical properties that arise from their twisted internal structure, and they may be useful for emerging applications..
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At the talk, MacLachlan mentioned that his new structurally iridescent material received great interest from the architectural community but since producing it was a painstaking process for a minute quantity, it would not be suitable as a building material.
A few years later I stumbled across some work at Cornell University where material scientists and Korean artist Kimsooja were working on what looks like an iridescent art/science piece, from a September 15, 2014 posting,
For her newest work, Korean artist Kimsooja wanted to explore a “shape and perspective that reveals the invisible as visible, physical as immaterial, and vice versa.” As artist-in-residence for the Cornell Council for the Arts’ (CCA) 2014 Biennial, she has realized that objective with “A Needle Woman: Galaxy was a Memory, Earth is a Souvenir,” to be installed on the Arts Quad next week [Sept. 15 – 19, 2014]. It will be one of several installations on campus for the semester-long biennial, “Intimate Cosmologies: The Aesthetics of Scale in an Age of Nanotechnology,” beginning Sept. 18 [2014] with a talk by Kimsooja.
Here’s how ‘Needle Woman’ looked after fabrication,
Jaeho Chong Pieces of Kimsooja’s “Needle Woman” artwork during fabrication in Shanghai show the polymer film developed by Cornell researchers
Creating materials that change color based on viewing angle represents a significant challenge at the intersection of art and science. Natural examples of this phenomenon, called iridescence, appear in butterfly wings, peacock feathers, and opals. Unlike traditional pigments that absorb specific wavelengths of light, these natural materials use microscopic structures to split light into different colors. This “structural color” approach creates pure, vibrant hues that don’t fade over time and require no potentially toxic pigments.
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A collaboration between Cornell University materials scientists and Korean-American artist Kimsooja has now yielded a practical solution to this challenge. The team developed a method for creating large-scale, durable iridescent coatings, demonstrated through a 46-foot-tall architectural installation titled A Needle Woman: Galaxy was a Memory, Earth is a Souvenir. Initially exhibited at Cornell under the auspices of the Cornell Council for the Arts, the installation now stands as part of the permanent collection at Yorkshire Sculpture Park in Wakefield, UK, where it has maintained its striking optical properties for over a decade.
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The breakthrough relies on custom-designed plastic molecules that automatically arrange themselves into regular patterns. These molecules consist of two different types of plastic chemically bonded together – polystyrene and poly(tert-butyl methacrylate). When properly designed, thousands of these dual-component molecules spontaneously stack into alternating layers, creating a natural grating that splits light into different colors.
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The key innovation came in synthesizing these molecules at unprecedented sizes – about 1000 times longer than typical plastic molecules. At this scale, the self-assembled layers naturally form patterns around 300-400 nanometers in spacing, large enough to interact with visible light. The researchers then developed a precise coating method to apply these materials while maintaining their self-organized structure.
The scale-up process presented numerous challenges. Each production batch yielded only about 35-40 grams of usable material, with half the attempts failing due to the extreme sensitivity to air and water during synthesis. The installation required roughly 500 grams of material to coat all panels. The team developed a custom two-liter reactor equipped with specialized mixing equipment to increase production scale while maintaining precise control over reaction conditions.
Color consistency posed another challenge. Different batches of the polymer produced slightly different colors due to variations in molecular size. The researchers developed two solutions: blending multiple batches to achieve consistent colors and adding precise amounts of shorter polymer chains to fine-tune the optical properties.
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The team also solved the challenge of applying these coatings to curved surfaces through a specialized lamination technique. They first created the color-shifting layer on flat, flexible plastic sheets, then sandwiched it between protective layers before carefully adhering it to curved acrylic panels. This approach preserved the optical properties while protecting the coating from environmental damage.
Molecules to Masterpieces: Bridging Materials Science and the Arts by Ferdinand F. E. Kohle, Hiroaki Sai, William R. T. Tait, Peter A. Beaucage, Ethan M. Susca, R. Paxton Thedford, Ulrich B. Wiesner. Advanced Materials DOI: https://doi.org/10.1002/adma.202413939. First published online: 05 December 2024
Both of these news bits are concerned with light for one reason or another.
Rice University (Texas, US) and breaking fluorocarbon bonds
The secret to breaking fluorocarbon bonds is light according to a June 22, 2020 news item on Nanowerk,
Rice University engineers have created a light-powered catalyst that can break the strong chemical bonds in fluorocarbons, a group of synthetic materials that includes persistent environmental pollutants.
In a study published this month in Nature Catalysis, Rice nanophotonics pioneer Naomi Halas and collaborators at the University of California, Santa Barbara (UCSB) and Princeton University showed that tiny spheres of aluminum dotted with specks of palladium could break carbon-fluorine (C-F) bonds via a catalytic process known as hydrodefluorination in which a fluorine atom is replaced by an atom of hydrogen.
The strength and stability of C-F bonds are behind some of the 20th century’s most recognizable chemical brands, including Teflon, Freon and Scotchgard. But the strength of those bonds can be problematic when fluorocarbons get into the air, soil and water. Chlorofluorocarbons, or CFCs, for example, were banned by international treaty in the 1980s after they were found to be destroying Earth’s protective ozone layer, and other fluorocarbons were on the list of “forever chemicals” targeted by a 2001 treaty.
“The hardest part about remediating any of the fluorine-containing compounds is breaking the C-F bond; it requires a lot of energy,” said Halas, an engineer and chemist whose Laboratory for Nanophotonics (LANP) specializes in creating and studying nanoparticles that interact with light.
Over the past five years, Halas and colleagues have pioneered methods for making “antenna-reactor” catalysts that spur or speed up chemical reactions. While catalysts are widely used in industry, they are typically used in energy-intensive processes that require high temperature, high pressure or both. For example, a mesh of catalytic material is inserted into a high-pressure vessel at a chemical plant, and natural gas or another fossil fuel is burned to heat the gas or liquid that’s flowed through the mesh. LANP’s antenna-reactors dramatically improve energy efficiency by capturing light energy and inserting it directly at the point of the catalytic reaction.
In the Nature Catalysis study, the energy-capturing antenna is an aluminum particle smaller than a living cell, and the reactors are islands of palladium scattered across the aluminum surface. The energy-saving feature of antenna-reactor catalysts is perhaps best illustrated by another of Halas’ previous successes: solar steam. In 2012, her team showed its energy-harvesting particles could instantly vaporize water molecules near their surface, meaning Halas and colleagues could make steam without boiling water. To drive home the point, they showed they could make steam from ice-cold water.
The antenna-reactor catalyst design allows Halas’ team to mix and match metals that are best suited for capturing light and catalyzing reactions in a particular context. The work is part of the green chemistry movement toward cleaner, more efficient chemical processes, and LANP has previously demonstrated catalysts for producing ethylene and syngas and for splitting ammonia to produce hydrogen fuel.
Study lead author Hossein Robatjazi, a Beckman Postdoctoral Fellow at UCSB who earned his Ph.D. from Rice in 2019, conducted the bulk of the research during his graduate studies in Halas’ lab. He said the project also shows the importance of interdisciplinary collaboration.
“I finished the experiments last year, but our experimental results had some interesting features, changes to the reaction kinetics under illumination, that raised an important but interesting question: What role does light play to promote the C-F breaking chemistry?” he said.
The answers came after Robatjazi arrived for his postdoctoral experience at UCSB. He was tasked with developing a microkinetics model, and a combination of insights from the model and from theoretical calculations performed by collaborators at Princeton helped explain the puzzling results.
“With this model, we used the perspective from surface science in traditional catalysis to uniquely link the experimental results to changes to the reaction pathway and reactivity under the light,” he said.
The demonstration experiments on fluoromethane could be just the beginning for the C-F breaking catalyst.
“This general reaction may be useful for remediating many other types of fluorinated molecules,” Halas said.
Caption: An artist’s illustration of the light-activated antenna-reactor catalyst Rice University engineers designed to break carbon-fluorine bonds in fluorocarbons. The aluminum portion of the particle (white and pink) captures energy from light (green), activating islands of palladium catalysts (red). In the inset, fluoromethane molecules (top) comprised of one carbon atom (black), three hydrogen atoms (grey) and one fluorine atom (light blue) react with deuterium (yellow) molecules near the palladium surface (black), cleaving the carbon-fluorine bond to produce deuterium fluoride (right) and monodeuterated methane (bottom). Credit: H. Robatjazi/Rice University
Called “robotic soft matter by the Northwestern team,” the materials move without complex hardware, hydraulics or electricity. The researchers believe the lifelike materials could carry out many tasks, with potential applications in energy, environmental remediation and advanced medicine.
“We live in an era in which increasingly smarter devices are constantly being developed to help us manage our everyday lives,” said Northwestern’s Samuel I. Stupp, who led the experimental studies. “The next frontier is in the development of new science that will bring inert materials to life for our benefit — by designing them to acquire capabilities of living creatures.”
The research will be published on June 22 [2020] in the journal Nature Materials.
Stupp is the Board of Trustees Professor of Materials Science and Engineering, Chemistry, Medicine and Biomedical Engineering at Northwestern and director of the Simpson Querrey Institute He has appointments in the McCormick School of Engineering, Weinberg College of Arts and Sciences and Feinberg School of Medicine. George Schatz, the Charles E. and Emma H. Morrison Professor of Chemistry in Weinberg, led computer simulations of the materials’ lifelike behaviors. Postdoctoral fellow Chuang Li and graduate student Aysenur Iscen, from the Stupp and Schatz laboratories, respectively, are co-first authors of the paper.
Although the moving material seems miraculous, sophisticated science is at play. Its structure comprises nanoscale peptide assemblies that drain water molecules out of the material. An expert in materials chemistry, Stupp linked the peptide arrays to polymer networks designed to be chemically responsive to blue light.
When light hits the material, the network chemically shifts from hydrophilic (attracts water) to hydrophobic (resists water). As the material expels the water through its peptide “pipes,” it contracts — and comes to life. When the light is turned off, water re-enters the material, which expands as it reverts to a hydrophilic structure.
This is reminiscent of the reversible contraction of muscles, which inspired Stupp and his team to design the new materials.
“From biological systems, we learned that the magic of muscles is based on the connection between assemblies of small proteins and giant protein polymers that expand and contract,” Stupp said. “Muscles do this using a chemical fuel rather than light to generate mechanical energy.”
For Northwestern’s bio-inspired material, localized light can trigger directional motion. In other words, bending can occur in different directions, depending on where the light is located. And changing the direction of the light also can force the object to turn as it crawls on a surface.
Stupp and his team believe there are endless possible applications for this new family of materials. With the ability to be designed in different shapes, the materials could play a role in a variety of tasks, ranging from environmental clean-up to brain surgery.
“These materials could augment the function of soft robots needed to pick up fragile objects and then release them in a precise location,” he said. “In medicine, for example, soft materials with ‘living’ characteristics could bend or change shape to retrieve blood clots in the brain after a stroke. They also could swim to clean water supplies and sea water or even undertake healing tasks to repair defects in batteries, membranes and chemical reactors.”
Fascinating, eh? No batteries, no power source, just light to power movement. For the curious, here’s a link to and a citation for the paper,
Supramolecular–covalent hybrid polymers for light-activated mechanical actuation by Chuang Li, Aysenur Iscen, Hiroaki Sai, Kohei Sato, Nicholas A. Sather, Stacey M. Chin, Zaida Álvarez, Liam C. Palmer, George C. Schatz & Samuel I. Stupp. Nature Materials (2020) DOI: https://doi.org/10.1038/s41563-020-0707-7 Published: 22 June 2020
First mentioned here in a Dec. 10, 2013 posting, Cornell University’s Cornell Council for the Arts (CCA; located in New York State) is hosting a 2014 Biennial celebrating this theme: “Intimate Cosmologies: The Aesthetics of Scale in an Age of Nanotechnology.” A Sept. 11, 2014 news item on Nanowerk describes the Biennial’s artist-in-residence Kimsooja and her work (Note: Links have been removed),
For her newest work, Korean artist Kimsooja wanted to explore a “shape and perspective that reveals the invisible as visible, physical as immaterial, and vice versa.”
As artist-in-residence for the Cornell Council for the Arts’ (CCA) 2014 Biennial, she has realized that objective with “A Needle Woman: Galaxy was a Memory, Earth is a Souvenir,” to be installed on the Arts Quad next week [Sept. 15 – 19, 2014]. It will be one of several installations on campus for the semester-long biennial, “Intimate Cosmologies: The Aesthetics of Scale in an Age of Nanotechnology,” beginning Sept. 18 [2014] with a talk by Kimsooja.
Here’s how ‘Needle Woman’ looked after fabrication,
Jaeho Chong Pieces of Kimsooja’s “Needle Woman” artwork during fabrication in Shanghai show the polymer film developed by Cornell researchers.
The biennial theme intends to “show how artists address realms of human experience that lie beyond our immediate sensory perception,” CCA Director Stephanie Owens said. “Working with scientists and researchers makes it possible to produce art at the edges between disciplines … generating lots of productivity and new thought.”
Kimsooja’s 46-foot-tall structure features an iridescent polymer film developed at Cornell, reflecting light with structural colors similar to those in a butterfly’s wings. Creating it involved some diligent problem-solving by materials scientists in the lab of Uli Wiesner, the Spencer T. Olin Professor of Engineering.
Owens first connected artists, musicians and scientists on campus in a series of lunchtime discussions two years ago, Wiesner said: “I thought, this is what I really wanted to have in a university, a place of knowledge – [where] you can do stuff that goes beyond borders.”
Last November, Wiesner met with Owens and Kimsooja. “My group brought a glass vial that had a block of polymer dissolved in a solvent. It had iridescent colors, like an opal,” he said. “When you turned it, it was dynamic; the solution would flow around, and the colors changed. And Kimsooja loved it and said, ‘This is what I want on my structure.’”
The group, including chemistry Ph.D. student Ferdinand Kohle and postdoctoral researcher Hiroaki Sai, worked out how to create a polymer producing the desired optical effect and how to adhere it to Plexiglas panels on Kimsooja’s structure. Architecture students assisted with materials and fabrication.
The Cornell news release describes other Biennial collaborations,
The biennial, Sept. 15-Dec. 21, is a deep survey of artistic and scientific exploration, framing changes in 21st-century culture, art practice and nanoscale technology through collaborative research-based projects by faculty and students and guest artists Rafael Lazano-Hemmer, Paul Thomas and Kevin Raxworthy, and the Particle Group artist collective.
Cornell faculty members Beth Milles, performing and media arts; Jenny Sabin, architecture; and Juan Hinestroza and Ruya Ozer, fiber science, with So Yeon-Yoon, design and environmental analysis, have all developed biennial projects on the nano theme with students.
“I really love how world-class science has been incorporated in world-class art,” Hinestroza said of the Kimsooja-Wiesner project. “The fundamental science behind the coatings developed by the Wiesner group, the chemistry developed by Hiro, as well as the methods pioneered to coat the films with such nanoscale precision by Ferdinand, are indeed revolutionary – and the use of these materials to assemble a large structure like Kimsooja’s needle is simply breathtaking.”
Architecture student Joseph Kennedy ’15 and Caio Barboza and Sunny Xu, both B.Arch. ’13, created “Paperthin,” an interactive installation in the Physical Sciences Building based on the textured landscape of a sheet of paper at nanoscale. Physics researcher Robert Hovden, Ph.D. ’14, created “When Art Exceeds Perception,” a series of imperceptible nano-scale engravings of famous works of art.
As part of the biennial, the CCA brought artists Joe Davis, Nathaniel Stern, Stephanie Rothenberg and Berndnaut Smilde to speak on campus last spring. Owens taught a related course, Micro Materialities/Macro Forms: Artistic Practice and the Culture of Nanoscience, in fall 2013.
“Artists that engage research as part of their process,” Owens said, “can find partnership and shared vision with like-minded pioneers in [other] disciplines … and in doing so, catalyze aspects of their work that can take on new and unexpected directions.”
Wish I could visit.
*’l’ added to ‘Biennial’ in head on February 4, 2025.
