A new smart material developed by researchers at the University of Waterloo is activated by both heat and electricity, making it the first ever to respond to two different stimuli.
The unique design paves the way for a wide variety of potential applications, including clothing that warms up while you walk from the car to the office in winter and vehicle bumpers that return to their original shape after a collision.
Inexpensively made with polymer nano-composite fibres from recycled plastic, the programmable fabric can change its colour and shape when stimuli are applied.
“As a wearable material alone, it has almost infinite potential in AI, robotics and virtual reality games and experiences,” said Dr. Milad Kamkar, a chemical engineering professor at Waterloo. “Imagine feeling warmth or a physical trigger eliciting a more in-depth adventure in the virtual world.”
The novel fabric design is a product of the happy union of soft and hard materials, featuring a combination of highly engineered polymer composites and stainless steel in a woven structure.
Researchers created a device similar to a traditional loom to weave the smart fabric. The resulting process is extremely versatile, enabling design freedom and macro-scale control of the fabric’s properties.
The fabric can also be activated by a lower voltage of electricity than previous systems, making it more energy-efficient and cost-effective. In addition, lower voltage allows integration into smaller, more portable devices, making it suitable for use in biomedical devices and environment sensors.
“The idea of these intelligent materials was first bred and born from biomimicry science,” said Kamkar, director of the Multi-scale Materials Design (MMD) Centre at Waterloo.
“Through the ability to sense and react to environmental stimuli such as temperature, this is proof of concept that our new material can interact with the environment to monitor ecosystems without damaging them.”
The next step for researchers is to improve the fabric’s shape-memory performance for applications in the field of robotics. The aim is to construct a robot that can effectively carry and transfer weight to complete tasks.
Caption: For their artificial fairy, Hao Zeng and Jianfeng Yang got inspired by dandelion seeds. Credit: Jianfeng Yang / Tampere University
That image makes me think of Tinker Bell (the fairy in the novel/play/movie with ‘Peter Pan’ in its titles) but I can also see how the researchers were inspired by dandelion seeds, which we used to call ‘wishes’.
The development of stimuli-responsive polymers has brought about a wealth of material-related opportunities for next-generation small-scale, wirelessly controlled soft-bodied robots. For some time now, engineers have known how to use these materials to make small robots that can walk, swim and jump. So far, no one has been able to make them fly.
Researchers of the Light Robots group at Tampere University [Finland] are now researching how to make smart material fly. Hao Zeng, Academy Research Fellow and the group leader, and Jianfeng Yang, a doctoral researcher, have come up with a new design for their project called FAIRY — Flying Aero-robots based on Light Responsive Materials Assembly. They have developed a polymer-assembly robot that flies by wind and is controlled by light.
Superior to its natural counterparts, this artificial seed is equipped with a soft actuator. The actuator is made of light-responsive liquid crystalline elastomer, which induces opening or closing actions of the bristles upon visible light excitation,” explains Hao Zeng.
The artificial fairy is controlled by light
The artificial fairy developed by Zeng and Yang has several biomimetic features. Because of its high porosity (0.95) and lightweight (1.2 mg) structure, it can easily float in the air directed by the wind. What is more, a stable separated vortex ring generation enables long-distance wind-assisted travelling.
“The fairy can be powered and controlled by a light source, such as a laser beam or LED,” Zeng says.
This means that light can be used to change the shape of the tiny dandelion seed-like structure. The fairy can adapt manually to wind direction and force by changing its shape. A light beam can also be used to control the take-off and landing actions of the polymer assembly.
Potential application opportunities in agriculture
Next, the researchers will focus on improving the material sensitivity to enable the operation of the device in sunlight. In addition, they will up-scale the structure so that it can carry micro-electronic devices such as GPS and sensors as well as biochemical compounds.
According to Zeng, there is potential for even more significant applications.
“It sounds like science fiction, but the proof-of-concept experiments included in our research show that the robot we have developed provides an important step towards realistic applications suitable for artificial pollination,” he reveals.
In the future, millions of artificial dandelion seeds carrying pollen could be dispersed freely by natural winds and then steered by light toward specific areas with trees awaiting pollination.
“This would have a huge impact on agriculture globally since the loss of pollinators due to global warming has become a serious threat to biodiversity and food production,” Zeng says.
Challenges remain to be solved
However, many problems need to be solved first. For example, how to control the landing spot in a precise way, and how to reuse the devices and make them biodegradable? These issues require close collaboration with materials scientists and people working on microrobotics.
The FAIRY project started in September 2021 and will last until August 2026. It is funded by the Academy of Finland. The flying robot is researched in cooperation with Dr. Wenqi Hu from Max Planck Institute for Intelligent Systems (Germany) and Dr. Hang Zhang from Aalto University.
I was hoping that there would be some insect audio files but this research is more about their role as inspiration for a new type of microphone than the sounds they make themselves. From a May 10, 2023 Acoustical Society of America news release (also on EurekAlert),
What can an insect hear? Surprisingly, quite a lot. Though small and simple, their hearing systems are highly efficient. For example, with a membrane only 2 millimeters across, the desert locust can decompose frequencies comparable to human capability. By understanding how insects perceive sound and using 3D-printing technology to create custom materials, it is possible to develop miniature, bio-inspired microphones.
The displacement of the wax moth Acroia grisella membrane, which is one of the key sources of inspiration for designing miniature, bio-inspired microphones. Credit: Andrew Reid
Andrew Reid of the University of Strathclyde in the U.K. will present his work creating such microphones, which can autonomously collect acoustic data with little power consumption. His presentation, “Unnatural hearing — 3D printing functional polymers as a path to bio-inspired microphone design,” will take place Wednesday, May 10 [2023], at 10:05 a.m. Eastern U.S. in the Northwestern/Ohio State room, as part of the 184th Meeting of the Acoustical Society of America running May 8-12 at the Chicago Marriott Downtown Magnificent Mile Hotel.
“Insect ears are ideal templates for lowering energy and data transmission costs, reducing the size of the sensors, and removing data processing,” said Reid.
Reid’s team takes inspiration from insect ears in multiple ways. On the chemical and structural level, the researchers use 3D-printing technology to fabricate custom materials that mimic insect membranes. These synthetic membranes are highly sensitive and efficient acoustic sensors. Without 3D printing, traditional, silicon-based attempts at bio-inspired microphones lack the flexibility and customization required.
“In images, our microphone looks like any other microphone. The mechanical element is a simple diaphragm, perhaps in a slightly unusual ellipsoid or rectangular shape,” Reid said. “The interesting bits are happening on the microscale, with small variations in thickness and porosity, and on the nanoscale, with variations in material properties such as the compliance and density of the material.”
More than just the material, the entire data collection process is inspired by biological systems. Unlike traditional microphones that collect a range of information, these microphones are designed to detect a specific signal. This streamlined process is similar to how nerve endings detect and transmit signals. The specialization of the sensor enables it to quickly discern triggers without consuming a lot of energy or requiring supervision.
The bio-inspired sensors, with their small size, autonomous function, and low energy consumption, are ideal for applications that are hazardous or hard to reach, including locations embedded in a structure or within the human body.
Bio-inspired 3D-printing techniques can be applied to solve many other challenges, including working on blood-brain barrier organoids or ultrasound structural monitoring.
I associate the idea of ‘creative destruction’ with economics and Joseph Schumpeter but it is more widespread and has a much longer history (see more at the end of this posting).
Here we have Université de Montréal researchers being inspired by the idea from (what was to me) an unexpected source, from a February 9, 2023 news item on Nanowerk,
“Every act of creation,” Picasso famously noted, “is first an act of destruction.”
Taking this concept literally, researchers in Canada have now discovered that “breaking” molecular nanomachines basic to life can create new ones that work even better.
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I love this image. Bravo!
Researchers Dominic Lauzon and Alexis Vallée-Bélisle Credit: Amélie Philibert & Benoit Gougeon | Université de Montréal
Life on Earth is made possible by tens of thousands of nanomachines that have evolved over millions of years. Often made of proteins or nucleic acids, they typically contain thousands of atoms and are less than 10,000 times the size of a human hair.
“These nanomachines control all molecular activities in our body, and problems with their regulation or structure are at the origin of most human diseases,” said the new study’s principal investigator Alexis Vallée-Bélisle, a chemistry professor at Université de Montréal.
Studying the way these nanomachines are built, Vallée-Bélisle, holder of the Canada Research Chair in Bioengineering and Bio-Nanotechnology, noticed that while some are made using a single component or part (often long biopolymers), others use several components that spontaneously assemble.
“Since most of my students spend their lives creating nanomachines, we started to wonder if it is more beneficial to create them using one or more self-assembling molecular components,” said Vallée-Bélisle.
A ‘destructive’ idea
To explore this question, his doctoral student Dominic Lauzon, had the “destructive” idea of breaking up some nanomachines to see if they could be reassembled. To do so, he made artificial DNA-based nanomachines that could be “destroyed” by breaking them up.
“DNA is a remarkable molecule that offers simple, programmable and easy-to-use chemistry,” said Lauzon, the study’s first author. “We believed that DNA-based nanomachines could help answer fundamental questions about the creation and evolution of natural and human-made nanomachines.”
Lauzon and Vallée-Bélisle spent years performing the experimental validations. They were able to demonstrate that nanomachines could easily withstand fragmentation, but more importantly, that such a destructive event allowed for the creation of various novel functionalities, including different sensitivity levels towards variation in component concentration, temperature and mutations.
What the researchers found is that these functionalities could arise simply by controlling the concentration of each individual component. For example, when cutting a nanomachine in three components, nanomachines were found to activate more sensitively at high concentration of components. In contrast, at low concentration of components, nanomachines could be programmed to activate or deactivate at specific moment in time or to simply inhibit their function.
“Overall, these novel functionalities were created by simply cutting up, or destroying, the structure of an existing nanomachine,” said Lauzon. “These functionalities could drastically improve human-based nanotechnologies such as sensors, drug carriers and even molecular computers”.
Evolving new functionalities
Just as Picasso typically destroyed dozens of unfinished works to create his famous artworks, and just like muscles need to break down to get stronger, and innovative new companies are born by eliminating older competitors from the market, nanoscale machines can evolve new functionalities by being taken apart.
Unlike common machines like cell phones, televisions and cars, which are made by combining components using screws and bolts, glue, solder or electronics, “nanomachines rely on thousands of weak dynamic intermolecular forces that can spontaneously reform, enabling broken nanomachines to re-assemble,” said Vallée-Bélisle.
In addition to providing nanotechnology researchers with a simple design strategy to create the next generation of nanomachines, the UdeM team’s findings also shed light on how natural molecular nanomachines may have evolved.
“Biologists have recently discovered that about 20 per cent of biological nanomachines may have evolved through the fragmentation of their genes,” said Vallée-Bélisle. “With our results, biologists now have a rational basis for understanding how the fragmentation of these ancestral proteins could have created new molecular functionalities for life on Earth.”
The Wikipedia entry for ‘Creative destruction’ is primarily on economic theory and various philosophies with no mention of Picasso. However, there is a fascinating segue into Eastern mysticism,
Other early usage
…
Hugo Reinert has argued that Sombart’s formulation of the concept was influenced by Eastern mysticism, specifically the image of the Hindu god Shiva, who is presented in the paradoxical aspect of simultaneous destroyer and creator.
An October 24, 2022 news item on Nanowerk announces new research from McGill University (Montréal, Canada),
Ice buildup on powerlines and electric towers brought the northern US and southern Canada to a standstill during the Great Ice Storm of 1998, leaving many in the cold and dark for days and even weeks. Whether it is on wind turbines, electric towers, drones, or airplane wings, dealing with ice buildup typically depends on techniques that are time consuming, costly and/or use a lot of energy, along with various chemicals.
But, by looking to nature, McGill researchers believe that they have found a promising new way of dealing with the problem. Their inspiration came from the wings of Gentoo penguins who swim in the ice-cold waters of the south polar region, with pelts that remain ice-free even when the outer surface temperature is well below freezing.
“We initially explored the qualities of the lotus leaf, which is very good at shedding water but proved less effective at shedding ice,” said Anne Kietzig, who has been looking for a solution for close to a decade. She is an associate professor in Chemical Engineering at McGill and the director of the Biomimetic Surface Engineering Laboratory. “It was only when we started investigating the qualities of penguin feathers that we discovered a material found in nature that was able to shed both water and ice.”
Fine wire mesh replicates water-shedding and ice-shedding qualities of feathers
“We found that the hierarchical arrangement of the feathers themselves provides water-shedding qualities, while their barbed surfaces lower the adhesion of ice,” explains Michael Wood, a recent PhD graduate who worked with Kietzig, who is one of the co-authors on a new paper in ACS Applied Material Interfaces. “We were able to replicate these combined effects through a laser-machined woven wire mesh.”
Kietzig adds, “It may seem counter intuitive, but the key to ice shedding is all the pores of the mesh which draw water in under freezing conditions. The water in these pores is the last to freeze, creating cracks when it expands, much like you see in the ice cube trays in your freezer. We need such little force to remove ice from our meshes because the crack in each of these pores easily snakes along the surface of those woven wires.”
Promising results from early tests
The researchers carried out wind-tunnel testing of surfaces covered by the steel mesh and found that the treatment was 95% more effective at resisting ice build up than an unenveloped sheet of polished stainless steel. Because there are no chemical treatments involved, the new approach provides a potentially maintenance-free solution to ice buildup on wind turbines, electric towers and power lines as well as drones.
“Given the number of regulations in place in passenger aviation and the risks involved, it is unlikely that airplane wings will ever be simply wrapped in metal mesh,” adds Kietzig. “It is, possible, however, that the surface of plane wings may one day incorporate the kind of texture that we are exploring, and that de-icing will occur thanks to a combination of traditional de-icing techniques working in concert in wing surfaces that incorporate surface texture inspired by penguin wings.”
Although more research is needed, the results thus far are promising.
The image on the left shows the microstructure of a penguin feather (the 10 micrometer closeup of the inset is the equivalent of 1/10th of the width of a human hair, to give a sense of scale) Those barbs, and barbules are branches off the feather’s central stem. The ‘hooks’ serve to attach individual feather hairs together into a mat. On the right is the stainless-steel wire cloth that the researchers decorated with nanogrooves that copy the hierarchy of the penguin feather structure (wire-like with nanogrooves on top). [downloaded from https://www.mcgill.ca/newsroom/channels/news/penguin-feathers-may-be-secret-effective-anti-icing-technology-342980]
Microprocessors in smartphones, computers, and data centers process information by manipulating electrons through solid semiconductors but our brains have a different system. They rely on the manipulation of ions in liquid to process information.
Inspired by the brain, researchers have long been seeking to develop ‘ionics’ in an aqueous solution. While ions in water move slower than electrons in semiconductors, scientists think the diversity of ionic species with different physical and chemical properties could be harnessed for richer and more diverse information processing.
Ionic computing, however, is still in its early days. To date, labs have only developed individual ionic devices such as ionic diodes and transistors, but no one has put many such devices together into a more complex circuit for computing — until now.
A team of researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), in collaboration with DNA Script, a biotech startup, have developed an ionic circuit comprising hundreds of ionic transistors and performed a core process of neural net computing.
The researchers began by building a new type of ionic transistor from a technique they recently pioneered. The transistor consists of an aqueous solution of quinone molecules, interfaced with two concentric ring electrodes with a center disk electrode, like a bullseye. The two ring electrodes electrochemically lower and tune the local pH around the center disk by producing and trapping hydrogen ions. A voltage applied to the center disk causes an electrochemical reaction to generate an ionic current from the disk into the water. The reaction rate can be sped up or down –– increasing or decreasing the ionic current — by tuning the local pH. In other words, the pH controls, or gates, the disk’s ionic current in the aqueous solution, creating an ionic counterpart of the electronic transistor.
They then engineered the pH-gated ionic transistor in such a way that the disk current is an arithmetic multiplication of the disk voltage and a “weight” parameter representing the local pH gating the transistor. They organized these transistors into a 16 × 16 array to expand the analog arithmetic multiplication of individual transistors into an analog matrix multiplication, with the array of local pH values serving as a weight matrix encountered in neural networks.
“Matrix multiplication is the most prevalent calculation in neural networks for artificial intelligence,” said Woo-Bin Jung, a postdoctoral fellow at SEAS and the first author of the paper. “Our ionic circuit performs the matrix multiplication in water in an analog manner that is based fully on electrochemical machinery.”
“Microprocessors manipulate electrons in a digital fashion to perform matrix multiplication,” said Donhee Ham, the Gordon McKay Professor of Electrical Engineering and Applied Physics at SEAS and the senior author of the paper. “While our ionic circuit cannot be as fast or accurate as the digital microprocessors, the electrochemical matrix multiplication in water is charming in its own right, and has a potential to be energy efficient.”
Now, the team looks to enrich the chemical complexity of the system.
“So far, we have used only 3 to 4 ionic species, such as hydrogen and quinone ions, to enable the gating and ionic transport in the aqueous ionic transistor,” said Jung. “It will be very interesting to employ more diverse ionic species and to see how we can exploit them to make rich the contents of information to be processed.”
The research was co-authored by Han Sae Jung, Jun Wang, Henry Hinton, Maxime Fournier, Adrian Horgan, Xavier Godron, and Robert Nicol. It was supported in part by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), under grant 2019-19081900002.
Here’s a link to and a citation for the paper,
An Aqueous Analog MAC Machine by Woo-Bin Jung, Han Sae Jung, Jun Wang, Henry Hinton, Maxime Fournier, Adrian Horgan, Xavier Godron, Robert Nicol, Donhee Ham. Advanced Materials DOI: https://doi.org/10.1002/adma.202205096 First published online: 23 August 2022
Photonic synapses with low power consumption and high sensitivity are expected to integrate sensing-memory-preprocessing capabilities
A new publication from Opto-Electronic Advances; DOI 10.29026/oea.2022.210069 discusses how photonic synapses with low power consumption and high sensitivity are expected to integrate sensing-memory-preprocessing capabilities.
Neuromorphic photonics/electronics is the future of ultralow energy intelligent computing and artificial intelligence (AI). In recent years, inspired by the human brain, artificial neuromorphic devices have attracted extensive attention, especially in simulating visual perception and memory storage. Because of its advantages of high bandwidth, high interference immunity, ultrafast signal transmission and lower energy consumption, neuromorphic photonic devices are expected to realize real-time response to input data. In addition, photonic synapses can realize non-contact writing strategy, which contributes to the development of wireless communication. The use of low-dimensional materials provides an opportunity to develop complex brain-like systems and low-power memory logic computers. For example, large-scale, uniform and reproducible transition metal dichalcogenides (TMDs) show great potential for miniaturization and low-power biomimetic device applications due to their excellent charge-trapping properties and compatibility with traditional CMOS processes. The von Neumann architecture with discrete memory and processor leads to high power consumption and low efficiency of traditional computing. Therefore, the sensor-memory fusion or sensor-memory- processor integration neuromorphic architecture system can meet the increasingly developing demands of big data and AI for low power consumption and high performance devices. Artificial synaptic devices are the most important components of neuromorphic systems. The performance evaluation of synaptic devices will help to further apply them to more complex artificial neural networks (ANN).
Chemical vapor deposition (CVD)-grown TMDs inevitably introduce defects or impurities, showed a persistent photoconductivity (PPC) effect. TMDs photonic synapses integrating synaptic properties and optical detection capabilities show great advantages in neuromorphic systems for low-power visual information perception and processing as well as brain memory.
The research Group of Optical Detection and Sensing (GODS) have reported a three-terminal photonic synapse based on the large-area, uniform multilayer MoS2 films. The reported device realized ultrashort optical pulse detection within 5 μs and ultralow power consumption about 40 aJ, which means its performance is much better than the current reported properties of photonic synapses. Moreover, it is several orders of magnitude lower than the corresponding parameters of biological synapses, indicating that the reported photonic synapse can be further used for more complex ANN. The photoconductivity of MoS2 channel grown by CVD is regulated by photostimulation signal, which enables the device to simulate short-term synaptic plasticity (STP), long-term synaptic plasticity (LTP), paired-pulse facilitation (PPF) and other synaptic properties. Therefore, the reported photonic synapse can simulate human visual perception, and the detection wavelength can be extended to near infrared light. As the most important system of human learning, visual perception system can receive 80% of learning information from the outside. With the continuous development of AI, there is an urgent need for low-power and high sensitivity visual perception system that can effectively receive external information. In addition, with the assistant of gate voltage, this photonic synapse can simulate the classical Pavlovian conditioning and the regulation of different emotions on memory ability. For example, positive emotions enhance memory ability and negative emotions weaken memory ability. Furthermore, a significant contrast in the strength of STP and LTP based on the reported photonic synapse suggests that it can preprocess the input light signal. These results indicate that the photo-stimulation and backgate control can effectively regulate the conductivity of MoS2 channel layer by adjusting carrier trapping/detrapping processes. Moreover, the photonic synapse presented in this paper is expected to integrate sensing-memory-preprocessing capabilities, which can be used for real-time image detection and in-situ storage, and also provides the possibility to break the von Neumann bottleneck.
I don’t have much to say about the research itself other than, I believe this is the first time I’ve seen a news release about neuromorphic computing research from China.
Group of Optical Detection and Sensing (GODS) [emphasis mine] was established in 2019. It is a research group focusing on compound semiconductors, lasers, photodetectors, and optical sensors. GODS has established a well-equipped laboratory with research facilities such as Molecular Beam Epitaxy system, IR detector test system, etc. GODS is leading several research projects funded by NSFC and National Key R&D Programmes. GODS have published more than 100 research articles in Nature Electronics, Light: Science and Applications, Advanced Materials and other international well-known high-level journals with the total citations beyond 8000.
Jiang Wu obtained his Ph.D. from the University of Arkansas Fayetteville in 2011. After his Ph.D., he joined UESTC as associate professor and later professor. He joined University College London [UCL] as a research associate in 2012 and then lecturer in the Department of Electronic and Electrical Engineering at UCL from 2015 to 2018. He is now a professor at UESTC [University of Electronic Science and Technology of China] [emphases mine]. His research interests include optoelectronic applications of semiconductor heterostructures. He is a Fellow of the Higher Education Academy and Senior Member of IEEE.
Opto-Electronic Advances (OEA) is a high-impact, open access, peer reviewed monthly SCI journal with an impact factor of 9.682 (Journals Citation Reports for IF 2020). Since its launch in March 2018, OEA has been indexed in SCI, EI, DOAJ, Scopus, CA and ICI databases over the time and expanded its Editorial Board to 36 members from 17 countries and regions (average h-index 49). [emphases mine]
The journal is published by The Institute of Optics and Electronics, Chinese Academy of Sciences, aiming at providing a platform for researchers, academicians, professionals, practitioners, and students to impart and share knowledge in the form of high quality empirical and theoretical research papers covering the topics of optics, photonics and optoelectronics.
The research group’s awkward name was almost certainly developed with the rather grandiose acronym, GODS, in mind. I don’t think you could get away with doing this in an English-speaking country as your colleagues would mock you mercilessly.
In a systematic evaluation of China’s Young Thousand Talents (YTT) program, which was established in 2010, researchers find that China has been successful in recruiting and nurturing high-caliber Chinese scientists who received training abroad. Many of these individuals outperform overseas peers in publications and access to funding, the study shows, largely due to access to larger research teams and better research funding in China. Not only do the findings demonstrate the program’s relative success, but they also hold policy implications for the increasing number of governments pursuing means to tap expatriates for domestic knowledge production and talent development. China is a top sender of international students to United States and European Union science and engineering programs. The YTT program was created to recruit and nurture the productivity of high-caliber, early-career, expatriate scientists who return to China after receiving Ph.Ds. abroad. Although there has been a great deal of international attention on the YTT, some associated with the launch of the U.S.’s controversial China Initiative and federal investigations into academic researchers with ties to China, there has been little evidence-based research on the success, impact, and policy implications of the program itself. Dongbo Shi and colleagues evaluated the YTT program’s first 4 cohorts of scholars and compared their research productivity to that of their peers that remained overseas. Shi et al. found that China’s YTT program successfully attracted high-caliber – but not top-caliber – scientists. However, those young scientists that did return outperformed others in publications across journal-quality tiers – particularly in last-authored publications. The authors suggest that this is due to YTT scholars’ greater access to larger research teams and better research funding in China. The authors say the dearth of such resources in the U.S. and E.U. “may not only expedite expatriates’ return decisions but also motivate young U.S.- and E.U.-born scientists to seek international research opportunities.” They say their findings underscore the need for policy adjustments to allocate more support for young scientists.
Kudos to the folks behind China’s Young Thousands Talents program! Jiang Wu’s career appears to be a prime example of the program’s success. Perhaps Canadian policy makers will be inspired.
Caption: Antheraea pernyi Credit: University of Bristol
As for how this creature’s wings might provide inspiration for sound absorbing wallpaper, there’s this June 14, 2022 news item on phys.org, Note: A link has been removed,
Experts at the University of Bristol have discovered that the scales on moth wings act as excellent sound absorbers even when placed on an artificial surface.
The researchers, who recently discovered that moth wings offer acoustic protection from bat echolocation calls, have been studying whether their structure could inform better performing sound absorbing panels when not moving in free space.
Bats and moths have been involved in an acoustic arms race between predator and prey ever since bats evolved echolocation some 65 million years ago. Moths are under huge predation pressure from bats and have evolved a plethora of defences in their strive for survival, but it’s the scales, on a moth wing, that hold the key to transforming noise-cancelling technology.
Prof Marc Holderied, of Bristol’s School of Biological Sciences, said: “What we needed to know first, was how well these moth scales would perform if they were in front of an acoustically highly reflective surface, such as a wall.
“We also needed to find out how the mechanisms of absorption might change when the scales were interacting with this surface.”
Prof Holderied and his team tested this by placing small sections of moth wings on an aluminium disc, then systematically tested how orientation of the wing with respect to the incoming sound and the removal of scale layers affected absorption.
Remarkably, they found that moth wings proved to be excellent sound absorbers, even when on top of an acoustical solid substrate, with the wings absorbing as much as 87% of the incoming sound energy. The effect is also broadband and omnidirectional, covering a wide range of frequencies and sound incident angles.
“What is even more impressive is that the wings are doing this whilst being incredibly thin, with the scale layer being only 1/50th of the thickness of the wavelength of the sound that they are absorbing,” explained lead author Dr Thomas Neil. “This extraordinary performance qualifies the moth wing as a natural occurring acoustic absorbing metasurface, a material that has unique properties and capabilities, that are not possible to create using conventional materials.”
The potential to create ultrathin sound absorbing panels has huge implications in building acoustics. As cities get louder, the need for efficient non-intrusive sound mitigation solutions grows. Equally, these lightweight sound absorbing panels could have huge impacts on the travel industry, with any weight saving in planes, cars and trains increasing efficiency in these modes of transport, reducing fuel use and CO2 emissions.
Now the scientists plan to replicate the sound absorbing performance by designing and building prototypes based on the sound absorbing mechanisms of the moth. The absorption that they have characterised in moth wing scales is all in the ultrasound frequency range, above that which humans can hear. Their next challenge is to design a structure that will work at lower frequencies whilst retaining the same ultrathin architecture employed by the moth.
Prof Holderied concluded: “Moths are going to inspire the next generation of sound absorbing materials.
“New research has shown that one day it will be possible to adorn the walls of your house with ultrathin sound absorbing wallpaper, using a design that copies the mechanisms that gives moths stealth acoustic camouflage.”
Here’s link to and a citation for the paper,
Moth wings as sound absorber metasurface by Thomas R. Neil, Zhiyuan Shen, Daniel Robert, Bruce W. Drinkwater and Marc W. Holderied. Proceedings of the Royal Society A Mathematical Physical and Engineering Sciences DOI: https://doi.org/10.1098/rspa.2022.0046 Published:15 June 2022
Researchers in the Department of Chemical and Biomolecular Engineering at the University of California, Irvine have invented a squid-skin inspired material that can wrap around a coffee cup to shield sensitive fingers from heat. They have also created a method for economically mass producing the adaptive fabric, making possible a wide range of uses. Credit: Melissa Sung Courtesy: University of California Irvine
I love that image. Melissa Sung, thank you. Sadly, squid-inspired cup cozies aren’t available yet according to a March 28, 2022 news item on phys.org but researchers are working on it, Note: Links have been removed,
In the future, you may have a squid to thank for your coffee staying hot on a cold day. Drawing inspiration from cephalopod skin, engineers at the University of California, Irvine invented an adaptive composite material that can insulate beverage cups, restaurant to-go bags, parcel boxes and even shipping containers.
The innovation is an infrared-reflecting metallized polymer film developed in the laboratory of Alon Gorodetsky, UCI associate professor of chemical and biomolecular engineering. In a paper published today [March 28, 2022] in Nature Sustainability, Gorodetsky and his team members describe a large-area composite material that regulates heat by means of reconfigurable metal structures that can reversibly separate from one another and come back together under different strain levels.
“The metal islands in our composite material are next to one another when the material is relaxed and become separated when the material is stretched, allowing for control of the reflection and transmission of infrared light or heat dissipation,” said Gorodetsky. “The mechanism is analogous to chromatophore expansion and contraction in a squid’s skin, which alters the reflection and transmission of visible light.”
Chromatophore size changes help squids communicate and camouflage their bodies to evade predators and hide from prey. Gorodetsky said by mimicking this approach, his team has enabled “tunable thermoregulation” in their material, which can lead to improved energy efficiency and protect sensitive fingers from hot surfaces.
A key breakthrough of this project was the UCI researchers’ development of a cost-effective production method of their composite material at application-relevant quantities. The copper and rubber raw materials start at about a dime per square meter with the costs reduced further by economies of scale, according to the paper. The team’s fabrication technique involves depositing a copper film onto a reusable substrate such as aluminum foil and then spraying multiple polymer layers onto the copper film, all of which can be done in nearly any batch size imaginable.
“The combined manufacturing strategy that we have now perfected in our lab is a real game changer,” said Gorodetsky. “We have been working with cephalopod-inspired adaptive materials and systems for years but previously have only been able to fabricate them over relatively small areas. Now there is finally a path to making this stuff roll-by-roll in a factory.”
The developed strategy and economies of scale should make it possible for the composite material to be used in a wide range of applications, from the coffee cup cozy up to tents, or in any container in which tunable temperature regulation is desired.
The invention will go easy on the environment due its environmental sustainability, said lead author Mohsin Badshah, a former UCI postdoctoral scholar in chemical and biomolecular engineering. “The composite material can be recycled in bulk by removing the copper with vinegar and using established commercial methods to repurpose the remaining stretchable polymer,” he said.
The team conducted universally relatable coffee cup testing in their laboratory on the UCI campus, where they proved they could control the cooling of the coffee. They were able to accurately and theoretically predict and then experimentally confirm the changes in temperature for the beverage-filled cups. The was also able to achieve a 20-fold modulation of infrared radiation transmittance and a 30-fold regulation of thermal fluxes under standardized testing conditions. The stable material even worked well for high levels of mechanical deformation and after repeated mechanical cycling.
“There is an enormous array of applications for this material,” said Gorodetsky. “Think of all the perishable goods that have been delivered to people’s homes during the pandemic. Any package that Amazon or another company sends that needs to be temperature-controlled can use a lining made from our squid-inspired adaptive composite material. Now that we can make large sheets of it at a time, we have something that can benefit many aspects of our lives.”
Joining Gorodetsky and Badshah on this project were Erica Leung, who recently graduated UCI with a Ph.D. in chemical and biomolecular engineering, and Aleksandra Strzelecka and Panyiming Liu, who are current UCI graduate students. The research was funded by the Defense Advanced Research Projects Agency, the Advanced Research Projects Agency – Energy and the Air Force Office of Scientific Research. A provisional patent for the technology and manufacturing process has been applied for.
Everyone knows that humans and most other vertebrate species hear using eardrums that turn soundwave pressure into signals for our brains. But what about smaller animals like insects and arthropods? Can they detect sounds? And if so, how?
Distinguished Professor Ron Miles, a Department of Mechanical Engineering faculty member at Binghamton University’s Thomas J. Watson College of Engineering and Applied Science, has been exploring that question for more than three decades, in a quest to revolutionize microphone technology.
A newly published study of orb-weaving spiders — the species featured in the classic children’s book “Charlotte’s Web” — has yielded some extraordinary results: The spiders are using their webs as extended auditory arrays to capture sounds, possibly giving spiders advanced warning of incoming prey or predators.
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Binghamton University (formal name: State University of New York at Binghamton) has made this fascinating (to me anyway) video available,
Binghamton University and Cornell University (also in New York state) researchers worked collaboratively on this project. Consequently, there are two news releases and there is some redundancy but I always find that information repeated in different ways is helpful for learning.
It is well-known that spiders respond when something vibrates their webs, such as potential prey. In these new experiments, researchers for the first time show that spiders turned, crouched or flattened out in response to sounds in the air.
The study is the latest collaboration between Miles and Ron Hoy, a biology professor from Cornell, and it has implications for designing extremely sensitive bio-inspired microphones for use in hearing aids and cell phone
Jian Zhou, who earned his PhD in Miles’ lab and is doing postdoctoral research at the Argonne National Laboratory, and Junpeng Lai, a current PhD student in Miles’ lab, are co-first authors. Miles, Hoy and Associate Professor Carol I. Miles from the Harpur College of Arts and Sciences’ Department of Biological Sciences at Binghamton are also authors for this study. Grants from the National Institutes of Health to Ron Miles funded the research.
A single strand of spider silk is so thin and sensitive that it can detect the movement of vibrating air particles that make up a soundwave, which is different from how eardrums work. Ron Miles’ previous research has led to the invention of novel microphone designs that are based on hearing in insects.
“The spider is really a natural demonstration that this is a viable way to sense sound using viscous forces in the air on thin fibers,” he said. “If it works in nature, maybe we should have a closer look at it.”
Spiders can detect miniscule movements and vibrations through sensory organs on their tarsal claws at the tips of their legs, which they use to grasp their webs. Orb-weaver spiders are known to make large webs, creating a kind of acoustic antennae with a sound-sensitive surface area that is up to 10,000 times greater than the spider itself.
In the study, the researchers used Binghamton University’s anechoic chamber, a completely soundproof room under the Innovative Technologies Complex. Collecting orb-weavers from windows around campus, they had the spiders spin a web inside a rectangular frame so they could position it where they wanted.
The team began by using pure tone sound 3 meters away at different sound levels to see if the spiders responded or not. Surprisingly, they found spiders can respond to sound levels as low as 68 decibels. For louder sound, they found even more types of behaviors.
They then placed the sound source at a 45-degree angle, to see if the spiders behaved differently. They found that not only are the spiders localizing the sound source, but they can tell the sound incoming direction with 100% accuracy.
To better understand the spider-hearing mechanism, the researchers used laser vibrometry and measured over one thousand locations on a natural spider web, with the spider sitting in the center under the sound field. The result showed that the web moves with sound almost at maximum physical efficiency across an ultra-wide frequency range.
“Of course, the real question is, if the web is moving like that, does the spider hear using it?” Miles said. “That’s a hard question to answer.”
Lai added: “There could even be a hidden ear within the spider body that we don’t know about.”
So the team placed a mini-speaker 5 centimeters away from the center of the web where the spider sits, and 2 millimeters away from the web plane — close but not touching the web. This allows the sound to travel to the spider both through air and through the web. The researchers found that the soundwave from the mini-speaker died out significantly as it traveled through the air, but it propagated readily through the web with little attenuation. The sound level was still at around 68 decibels when it reached the spider. The behavior data showed that four out of 12 spiders responded to this web-borne signal.
Those reactions proved that the spiders could hear through the webs, and Lai was thrilled when that happened: “I’ve been working on this research for five years. That’s a long time, and it’s great to see all these efforts will become something that everybody can read.”
The researchers also found that, by crouching and stretching, spiders may be changing the tension of the silk strands, thereby tuning them to pick up different frequencies. By using this external structure to hear, the spider could be able to customize it to hear different sorts of sounds.
Future experiments may investigate how spiders make use of the sound they can detect using their web. Additionally, the team would like to test whether other types of web-weaving spiders also use their silk to outsource their hearing.
“It’s reasonable to guess that a similar spider on a similar web would respond in a similar way,” Ron Miles said. “But we can’t draw any conclusions about that, since we tested a certain kind of spider that happens to be pretty common.”
Lai admitted he had no idea he would be working with spiders when he came to Binghamton as a mechanical engineering PhD student.
“I’ve been afraid of spiders all my life, because of their alien looks and hairy legs!” he said with a laugh. “But the more I worked with spiders, the more amazing I found them. I’m really starting to appreciate them.”
Charlotte’s web is made for more than just trapping prey.
A study of orb weaver spiders finds their massive webs also act as auditory arrays that capture sounds, possibly giving spiders advanced warning of incoming prey or predators.
In experiments, the researchers found the spiders turned, crouched or flattened out in response to sounds, behaviors that spiders have been known to exhibit when something vibrates their webs.
The paper, “Outsourced Hearing in an Orb-weaving Spider That Uses its Web as an Auditory Sensor,” published March 29 [2022] in the Proceedings of the National Academy of Sciences, provides the first behavioral evidence that a spider can outsource hearing to its web.
The findings have implications for designing bio-inspired extremely sensitive microphones for use in hearing aids and cell phones.
A single strand of spider silk is so thin and sensitive it can detect the movement of vibrating air particles that make up a sound wave. This is different from how ear drums work, by sensing pressure from sound waves; spider silk detects sound from nanoscale air particles that become excited from sound waves.
“The individual [silk] strands are so thin that they’re essentially wafting with the air itself, jostled around by the local air molecules,” said Ron Hoy, the Merksamer Professor of Biological Science, Emeritus, in the College of Arts and Sciences and one of the paper’s senior authors, along with Ronald Miles, professor of mechanical engineering at Binghamton University.
Spiders can detect miniscule movements and vibrations via sensory organs in their tarsi – claws at the tips of their legs they use to grasp their webs, Hoy said. Orb weaver spiders are known to make large webs, creating a kind of acoustic antennae with a sound-sensitive surface area that is up to 10,000 times greater than the spider itself.
In the study, the researchers used a special quiet room without vibrations or air flows at Binghamton University. They had an orb-weaver build a web inside a rectangular frame, so they could position it where they wanted. The team began by putting a mini-speaker within millimeters of the web without actually touching it, where sound operates as a mechanical vibration. They found the spider detected the mechanical vibration and moved in response.
They then placed a large speaker 3 meters away on the other side of the room from the frame with the web and spider, beyond the range where mechanical vibration could affect the web. A laser vibrometer was able to show the vibrations of the web from excited air particles.
The team then placed the speaker in different locations, to the right, left and center with respect to the frame. They found that the spider not only detected the sound, it turned in the direction of the speaker when it was moved. Also, it behaved differently based on the volume, by crouching or flattening out.
Future experiments may investigate whether spiders rebuild their webs, sometimes daily, in part to alter their acoustic capabilities, by varying a web’s geometry or where it is anchored. Also, by crouching and stretching, spiders may be changing the tension of the silk strands, thereby tuning them to pick up different frequencies, Hoy said.
Additionally, the team would like to test if other types of web-weaving spiders also use their silk to outsource their hearing. “The potential is there,” Hoy said.
Miles’ lab is using tiny fiber strands bio-inspired by spider silk to design highly sensitive microphones that – unlike conventional pressure-based microphones – pick up all frequencies and cancel out background noise, a boon for hearing aids.
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Here’s a link to and a citation for the paper,
Outsourced hearing in an orb-weaving spider that uses its web as an auditory sensor by Jian Zhou, Junpeng Lai, Gil Menda, Jay A. Stafstrom, Carol I. Miles, Ronald R. Hoy, and Ronald N. Miles. Proceedings of the National Academy of Sciences (PNAS) DOI: https://doi.org/10.1073/pnas.2122789119 Published March 29, 2022 | 119 (14) e2122789119
This paper appears to be open access and video/audio files are included (you can heat the sound and watch the spider respond).
