Category Archives: biomimcry

Growing plant roots and fungal hyphae in silica nanoparticles for 3D microvascular networks

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This is fascinating,

A November 19, 2024 news item on phys.org describes the problem the researchers in Japan were solving,

Microfluidic technology has become increasingly important in many scientific fields, such as regenerative medicine, microelectronics, and environmental science. However, conventional microfabrication techniques face limitations in scale and in the construction of complex networks. These hurdles are compounded when it comes to building more intricate 3D microfluidic networks.

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A November 19, 2024 Kyushu University press release (also on EurekAlert), which originated the news item, describes how the researchers propose to solve the problem building 3D microfluidic networks, Note: Links have been removed,

Now, researchers from Kyushu University have developed a new and convenient technique for building such complex 3D microfluidic networks. Their tool? Plants and fungi. The team developed a ‘soil’ medium using nanoparticles of glass (silica) and a cellulose based binding agent, then allowed plants and fungi to grow roots into it. After the plants were removed, the glass was left with a complex 3D microfluidic network of micrometer-sized hollow holes where the roots once were.

The new method can also be utilized for observing and preserving 3D biological structures that are typically difficult to study in soil, opening new opportunities for research in plant and fungal biology. Their findings were published in the journal Scientific Reports.

“The primary motivation for this research was to overcome the limitations of conventional microfabrication techniques in creating complex 3D microfluidic structures. The focus of our lab is biomimetics, where we try to solve engineering problems by looking to nature and artificially replicating such structures,” explains Professor Fujio Tsumori of Kyushu University’s Faculty of Engineering, who led the study. “And what better example of microfluidics in nature than plant roots and fungal hyphae? So, we set out to develop a method that could harness the natural growth patterns of these organisms and create optimized microfluidic networks.”

The researchers began by developing a ‘soil’ like mix for plants to grow in, but instead of dirt, they combined growth medium with glass nanoparticles smaller than 1 μm in diameter with hydroxypropyl methyl cellulose as a binding agent. They then seeded this ‘soil’ mixture and waited for the plants to take root. After confirming successful plant growth, the ‘soil’ was baked leaving only the glass with root cavities.

“The process is called sintering, which aggregates fine particles together into a more solid state. It is similar to powder metallurgy in the manufacturing of ceramics,” continues Tsumori. “In this case it is the plant that does the molding.”

Their method was able to replicate the intricate biological structures of a plant’s main roots which can be up to 150 μm in diameter, and all the way down to it root hairs which can be about 8 μm in diameter. Tests with other organisms showed that the method can even replicate the root structure of fungi, called hyphae.

“Hyphae are even thinner and can be as small as 1-2 μm in diameter. That’s thinner than a single strand of spider silk,” says Tsumori.

The team hopes that their new bio-inspired microfluidic fabrication technique could be used in various fields of science and engineering, potentially leading to more efficient microreactors, advanced heat exchangers, and innovative tissue engineering scaffolds.

“In the biological sciences, this technique provides a unique tool for studying the intricate 3D structures of plant roots and fungal networks, which can advance our understanding of soil ecosystems,” concludes Tsumori. “By bridging biological systems and engineering, our research has the potential to pave the way for new technologies and scientific discoveries.”

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About Kyushu University 
Founded in 1911, Kyushu University is one of Japan’s leading research-oriented institutes of higher education, consistently ranking as one of the top ten Japanese universities in the Times Higher Education World University Rankings and the QS World Rankings. The university is one of the seven national universities in Japan, located in Fukuoka, on the island of Kyushu—the most southwestern of Japan’s four main islands with a population and land size slightly larger than Belgium. Kyushu U’s multiple campuses—home to around 19,000 students and 8000 faculty and staff—are located around Fukuoka City, a coastal metropolis that is frequently ranked among the world’s most livable cities and historically known as Japan’s gateway to Asia. Through its VISION 2030, Kyushu U will “drive social change with integrative knowledge.” By fusing the spectrum of knowledge, from the humanities and arts to engineering and medical sciences, Kyushu U will strengthen its research in the key areas of decarbonization, medicine and health, and environment and food, to tackle society’s most pressing issues.

Here’s a link to and a citation for the paper,

Replicating biological 3D root and hyphal networks in transparent glass chips by Tetsuro Koga, Shota Nakashima & Fujio Tsumori. Scientific Reports volume 14, Article number: 21128 (2024) DOI: https://doi.org/10.1038/s41598-024-72333-y Published: 10 September 2024

This paper is open access.

Miniature, soft lithium-ion battery constructed from biocompatible hydrogel droplets for bio-integrated devices

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The original headline for the University of Oxford press release was “Batteries for miniature bio-integrated devices and robotics” but it’s not clear to me what they mean by robotics (soft robots? robotic prostheses? something else?).

An October 25, 2024 news item on ScienceDaily announces the research,

University of Oxford researchers have made a significant step towards realising miniature, soft batteries for use in a variety of biomedical applications, including the defibrillation and pacing of heart tissues. The work has been published today [October 25, 2024] in the journal Nature Chemical Engineering.

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An October 28, 2024 University of Oxford press release (also on EurekAlert but published October 25, 2024), which originated the lightly edited news item and posting on EurekAlert, provides more technical detail about this advance, Note: Links have been removed,

The development of tiny smart devices, smaller than a few cubic millimeters, demands equally small power sources. For minimally invasive biomedical devices that interact with biological tissues, these power sources must be fabricated from soft materials. Ideally, these should also have features such as high capacity, biocompatibility and biodegradability, triggerable activation, and the ability to be controlled remotely. To date, there has been no battery that can fulfil these requirements all at once.

To address these requirements, researchers from the University of Oxford’s Department of Chemistry and Department of Pharmacology have developed a miniature, soft lithium-ion battery constructed from biocompatible hydrogel droplets. Surfactant-supported assembly (assembly aided by soap-like molecules), a technique reported by the same group last year in the journal Nature (DOI: 10.1038/s41586-023-06295-y), is used to connect three microscale droplets of 10 nanolitres volume. Different lithium-ion particles contained in each of the two ends then generate the output energy.

‘Our droplet battery is light-activated, rechargeable, and biodegradable after use. To date, it is the smallest hydrogel lithium-ion battery and has a superior energy density’ said Dr Yujia Zhang (Department of Chemistry, University of Oxford), the lead researcher for the study and a starting Assistant Professor at the École Polytechnique Fédérale de Lausanne. ‘We used the droplet battery to power the movement of charged molecules between synthetic cells and to control the beating and defibrillation of mouse hearts. By including magnetic particles to control movement, the battery can also function as a mobile energy carrier.’

Proof-of-concept heart treatments were carried out in the laboratory of Professor Ming Lei (Department of Pharmacology), a senior electrophysiologist in cardiac arrhythmias. He said: ‘Cardiac arrhythmia is a leading cause of death worldwide. Our proof-of-concept application in animal models demonstrates an exciting new avenue of wireless and biodegradable devices for the management of arrhythmias.’

Professor Hagan Bayley (Department of Chemistry), the research group leader for the study, said: ‘The tiny soft lithium-ion battery is the most sophisticated in a series of microscale power packs developed by Dr Zhang and points to a fantastic future for biocompatible electronic devices that can operate under physiological conditions.’

The researchers have filed a patent application through Oxford University Innovation. They envisage that the tiny versatile battery, particularly relevant to small-scale robots for bioapplications, will open up new possibilities in various areas including clinical medicine.

Here’s a link to and a citation for the paper,

A microscale soft lithium-ion battery for tissue stimulation by Yujia Zhang, Tianyi Sun, Xingyun Yang, Linna Zhou, Cheryl M. J. Tan, Ming Lei & Hagan Bayley. Nature Chemical Engineering volume 1, pages 691–701 (2024) DOI: https://doi.org/10.1038/s44286-024-00136-z Published online: 25 October 2024 Issue Date: November 2024

This paper is open access.

Now, I want to highlight a few items from the paper’s introduction, Note: Links have been removed,

The miniaturization of electronic devices is a burgeoning area of research1,2,3. Therefore, the development of tiny batteries to power these devices is of critical importance, and techniques such as three-dimensional (3D) printing4,5,6 and micro-origami assembly7 [emphases mine] are beginning to have an impact. For minimally invasive applications in biomedicine, batteries are also preferred to be soft, biocompatible and biodegradable, with additional functionality and responsiveness, such as triggerable activation and remote-controlled mobility8. However, at present, such a multifunctional microscale soft battery is not available. Although hydrogel-based lithium-ion (Li-ion) batteries demonstrate some of these features9,10,11,12, none currently exhibits microscale fabrication of the battery architecture, in terms of self-assembled integration of hydrogel-based cathode, separator and anode at the submillimeter level. Manual assembly of precrosslinked compartments11 or multistep deposition and crosslinking4 is necessary to avoid the mixing of materials from different compartments at the pregel (liquid) state or during the gelation process. This limitation not only makes it difficult to shrink hydrogel-based functional architectures but also hinders the implementation of high-density energy storage.

Toward that end, Zhang et al. have reported a miniaturized ionic power source by depositing lipid-supported networks of nanoliter hydrogel droplets13. The power source mimics the electrical eel [emphasis mine] by using internal ion gradients to generate ionic current14, and can induce neuronal modulation. However, the ionic power source has several limitations [emphasis mine] that should be addressed. First, the stored salt gradient produces less power than conventional Li-ion batteries, and the device cannot be fully recharged. Second, activation of the power source relies on temperature-triggered gelation and oil for buffer exchange, which is a demanding requirement. Third, the functionality of the power source is limited to the generation of ionic output, leaving the full versatility of synthetic tissues unexploited15,16,17. Last, but not least, while the power source can modulate the activity of neural microtissues, organ-level stimulation necessitates a higher and more stable output performance in physiological environments18.

Here, we present a miniature, soft, rechargeable Li-ion droplet battery (LiDB) made by depositing self-assembling [emphasis mine], nanoliter, lipid-supported, silk hydrogel droplets. The tiny hydrogel compartmentalization produces a superior energy density. The battery is switched on by ultraviolet (UV) light, which crosslinks the hydrogel and breaks the lipid barrier between droplets. The droplets are soft, biocompatible and biodegradable. The LiDBs can power charge molecule translocation between synthetic cells, defibrillate mouse hearts with ventricular arrhythmias and pace heart rhythms. Further, the LiDB can be translocated from one site to another magnetically.

This team has integrated a number of cutting edge (I think you can still call them that) techniques such as 3D printing and origami along with inspiration from electric eels (biomimicry) for using light as a power source. .Finally, there’s self-assembly or, as it’s sometimes known, bottom-up engineering, just like nature.

This work still needs to be tested in human clinical trials but taking that into account: Bravo to the researchers!

Fungus-controlled robots

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Where robots are concerned, mushrooms and other fungi aren’t usually considered as part of the equipment but one would be wrong according to a September 4, 2024 news item on ScienceDaily,

Building a robot takes time, technical skill, the right materials — and sometimes, a little fungus.

In creating a pair of new robots, Cornell University researchers cultivated an unlikely component, one found on the forest floor: fungal mycelia.

By harnessing mycelia’s innate electrical signals, the researchers discovered a new way of controlling “biohybrid” robots that can potentially react to their environment better than their purely synthetic counterparts.

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An August 28, 2024 Cornell University news release (also on EurekAlert but published August 29, 2024) by David Nutt, which originated the news item, describes this (I’m tempted to call it, revolutionary) new technique, Note: Links have been removed.

“This paper is the first of many that will use the fungal kingdom to provide environmental sensing and command signals to robots to improve their levels of autonomy,” Shepherd [Rob Shepherd, professor of mechanical and aerospace engineering at Cornell University] said. “By growing mycelium into the electronics of a robot, we were able to allow the biohybrid machine to sense and respond to the environment. In this case we used light as the input, but in the future it will be chemical. The potential for future robots could be to sense soil chemistry in row crops and decide when to add more fertilizer, for example, perhaps mitigating downstream effects of agriculture like harmful algal blooms.”

In designing the robots of tomorrow, engineers have taken many of their cues from the animal kingdom, with machines that mimic the way living creatures move, sense their environment and even regulate their internal temperature through perspiration. Some robots have incorporated living material, such as cells from muscle tissue, but those complex biological systems are difficult to keep healthy and functional. It’s not always easy, after all, to keep a robot alive.

Mycelia are the underground vegetative part of mushrooms, and they have a number of advantages. They can grow in harsh conditions. They also have the ability to sense chemical and biological signals and respond to multiple inputs.

“If you think about a synthetic system – let’s say, any passive sensor – we just use it for one purpose. But living systems respond to touch, they respond to light, they respond to heat, they respond to even some unknowns, like signals,” Mishra [Anand Mishra, a research associate in the Organic Robotics Lab at Cornell University] said. “That’s why we think, OK, if you wanted to build future robots, how can they work in an unexpected environment? We can leverage these living systems, and any unknown input comes in, the robot will respond to that.”

However, finding a way to integrate mushrooms and robots requires more than just tech savvy and a green thumb.

“You have to have a background in mechanical engineering, electronics, some mycology, some neurobiology, some kind of signal processing,” Mishra said. “All these fields come together to build this kind of system.”

Mishra collaborated with a range of interdisciplinary researchers. He consulted with Bruce Johnson, senior research associate in neurobiology and behavior, and learned how to record the electrical signals that are carried in the neuron-like ionic channels in the mycelia membrane. Kathie Hodge, associate professor of plant pathology and plant-microbe biology in the School of Integrative Plant Science in the College of Agriculture and Life Sciences, taught Mishra how to grow clean mycelia cultures, because contamination turns out to be quite a challenge when you are sticking electrodes in fungus.

The system Mishra developed consists of an electrical interface that blocks out vibration and electromagnetic interference and accurately records and processes the mycelia’s electrophysiological activity in real time, and a controller inspired by central pattern generators – a kind of neural circuit. Essentially, the system reads the raw electrical signal, processes it and identifies the mycelia’s rhythmic spikes, then converts that information into a digital control signal, which is sent to the robot’s actuators.

Two biohybrid robots were built: a soft robot shaped like a spider and a wheeled bot.

The robots completed three experiments. In the first, the robots walked and rolled, respectively, as a response to the natural continuous spikes in the mycelia’s signal. Then the researchers stimulated the robots with ultraviolet light, which caused them to change their gaits, demonstrating mycelia’s ability to react to their environment. In the third scenario, the researchers were able to override the mycelia’s native signal entirely.

The implications go far beyond the fields of robotics and fungi.

“This kind of project is not just about controlling a robot,” Mishra said. “It is also about creating a true connection with the living system. Because once you hear the signal, you also understand what’s going on. Maybe that signal is coming from some kind of stresses. So you’re seeing the physical response, because those signals we can’t visualize, but the robot is making a visualization.”

Co-authors include Johnson, Hodge, Jaeseok Kim with the University of Florence, Italy, and undergraduate research assistant Hannah Baghdadi.

The research was supported by the National Science Foundation (NSF) CROPPS Science and Technology Center; the U.S. Department of Agriculture’s National Institute of Food and Agriculture; and the NSF Signal in Soil program.

Here’s a link to and a citation for the paper,

Sensorimotor control of robots mediated by electrophysiological measurements of fungal mycelia by Anand Kumar Mishra, Jaeseok Kim, Hannah Baghdadi, Bruce R. Johnson, Kathie T. Hodge, and Robert F. Shepherd. Science Robotics 28 Aug 2024 Vol 9, Issue 93 DOI: 10.1126/scirobotics.adk8019

This paper is behind a paywall.

Nature-inspired metalworking: from shrimp to steel

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Caption: Metallic replica of a honeybee’s (Apis mellifera) head, created at room temperature and pressure, using the same principles insects use to form their exoskeleton. Credit: SUTD

An August 15, 2024 Singapore University of Technology and Design press release on EurrekAlert announced research on nature-inspired metalworking, Note: A link has been removed,

Humans have long turned to nature for solutions, from deciphering the mysteries of flight to creating stronger materials. For Javier Fernandez, Associate Professor at the Singapore University of Technology and Design (SUTD), nature is a blueprint for sustainability. “Unlike our society’s energy-intensive engineering, nature operates under a paradigm of scarcity and finds solutions without access to intense energy sources or transport of materials,” he observed.

Chitin, found everywhere in nature ranging from shrimp to seashells and mushrooms, is an organic material that deserves a closer look. In addition to being the second most abundant organic material on Earth, it is strong and lightweight, making it an ideal material for many engineering applications.

“Chitin also has a strong affinity for metals,” said Assoc Prof Fernandez. “We decided to evaluate whether this affinity, combined with the processes that shape the cuticle, could be used to produce functional metallic structures in a ‘biological’ way.”

In the natural world, metals, while rarely used, can be found in some chitinous structures, such as the cuticles and exoskeletons of insects and crustaceans. By digging deeper into the affinity that chitins and their derivatives have for metals, Fernandez and his team designed a new approach to metalworking, which they published in their paper, “A biological approach to metalworking based on chitinous colloids and composites”, in the journal Advanced Functional Materials.

Through the use of design and technology inspired by these chitinous compounds, the research team demonstrated a novel way of producing functional metallic structures without the usual energy costs.

In traditional metalworking, high temperatures and pressures are essential to melt and shape metals. This stands in stark contrast to how metals are incorporated into chitinous materials in nature, which happens under ambient conditions. Take the metallic compounds found in arthropod cuticles like crab shells for example. Typically, the metals only make their way into the crab shell at the later stages of chitin development—the chitin would first stiffen into a shell through tanning and dehydration before any metal from the environment gets added to it.

This is similar to how metal compounds might also be introduced to chitosan, a derivative of chitin, as the researchers discovered in their experiments. They were able to form solid metallic composites under standard temperature and pressure just by introducing very small amounts of chitosan and water between particles of different metals. When the water evaporates, the chitosan molecules replicate the consolidation process in the cuticles, pulling the particles together with such strength that they become a continuous solid of 99.5% metal. Fernandez likens the fabrication process to concrete formation, explaining, “By pouring metal particles into dissolved chitosan and letting them ‘dry’, we can form massive metallic parts without the constraints of melting.”

While these chitometallic composites were not physically strong, the researchers found that the material acquired good electrical conductivity and could be 3D-printed. At the same time, the material continued to show compatibility with other biomaterials despite only containing a small amount of chitosan. This opens up the possibility of introducing these chitometallic properties into other biomaterials, such as wood and cellulose.

Fernandez believes this technology creates a new paradigm of metalworking. Despite the lack of mechanical strength, the fabricated biomaterial is suitable for non-load-bearing metallic components, such as electrical components or battery electrodes. Metalwork for some components can now be performed without being resource-intensive. “This technology does not replace traditional methods but enables new complementary production methods,” he emphasised.

Since then, Fernandez’s team has successfully filed a patent for the innovative fabrication method and is now looking into designing a new technology to develop biodegradable 3D electronic components, which can pave the way for more efficient and sustainable methods of production.

Here’s a link to and a citation for the paper,

A Biological Approach to Metalworking Based on Chitinous Colloids and Composites by Shiwei Ng, Guan Zhi Benjamin Ng, Robert E. Simpson, Javier G. Fernandez. Advanced Functional Materials DOI: https://doi.org/10.1002/adfm.202406800 First published: 24 July 2024

This paper is behind a paywall.

First-of-its-kind thermally-insulated and breathable soft robotic clothing for use in extreme heat

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An August 15, 2024 news item on ScienceDaily announces research that may help make people safer in extreme heat,

As global warming intensifies, people increasingly suffer from extreme heat. For those working in a high-temperature environment indoors or outdoors, keeping thermally comfortable becomes particularly crucial. A team led by Dr Dahua SHOU, Limin Endowed Young Scholar in Advanced Textiles Technologies and Associate Professor of the School of Fashion and Textiles of The Hong Kong Polytechnic University (PolyU) has developed first-of-its-kind thermally-insulated and breathable soft robotic clothing that can automatically adapt to changing ambient temperatures, thereby helping to ensure worker safety in hot environments. Their research findings have been published in the international interdisciplinary journal Advanced Science.

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An August 14, 2024 Hong Kong Polytechnic University press release (also on EurekAlert but published on August 15, 2024), which originated the news item, elaborates on the issue and on the proposed solution,

Maintaining a constant body temperature is one of the most critical requirements for living and working. High-temperature environments elevate energy consumption, leading to increased heat stress, thus exacerbating chronic conditions such as cardiovascular disease, diabetes, mental health issues and asthma, while also increasing the risk of infectious disease transmission. According to the World Health Organisation, globally, there were approximately 489,000 heat-related deaths annually between 2000 and 2019, with 45% occurring in Asia and 36% in Europe.

Thermal protective clothing is essential to safeguard individuals in extreme high-temperature environments, such as firefighters who need to be present at fires [sic] scenes and construction workers who work outdoors for extended periods. However, traditional gear has been limited by statically fixed thermal resistance, which can lead to overheating and discomfort in moderate conditions, while its heat insulation may not offer sufficient protection in extreme fire events and other high-temperature environments. To address this issue, Dr Shou and his team have developed intelligent soft robotic clothing for automatic temperature adaptation and thermal insulation in hot environments, offering superior personal protection and thermal comfort across a range of temperatures.

Their research was inspired by biomimicry in nature, like the adaptive thermal regulation mechanism in pigeons, which is mainly based on structural changes. Pigeons use their feathers to trap a layer of air surrounding their skin to reduce heat loss to the environment. When the temperature drops, they fluff up their feathers to trap a significant amount of still air, thereby increasing thermal resistance and retaining warmth.

The protective clothing developed by the team uses soft robotic textile for dynamic adaptive thermal management. Soft actuators, designed like a human network-patterned exoskeleton and encapsulating a non-toxic, non-flammable, low-boiling-point fluid, were strategically embedded within the clothing. This thermo-stimulated system turns the fluid from a liquid into a gas when the ambient temperature rises, causing expansion of soft actuators and thickening the textile matrix, thereby enhancing the gap of still air and doubling the thermal resistance from 0.23 to 0.48 Km²/W. The protective clothing can also keep the inner surface temperatures at least 10°C cooler than conventional heat-resistant clothing, even when the outer surface reaches 120°C.

This unique soft robotic textile, made by thermoplastic polyurethane, is soft, resilient and durable. Notably, it is far more skin-friendly and conformable than temperature-responsive clothing embedded with shape-memory alloys and is adjustable for a wide range of protective clothing. The soft actuators have exhibited no signs of leakage after undergoing rigorous standard washing tests. The porous, spaced knitting structure of the material can also significantly reduce convective heat transfer while maintaining high moisture breathability. Not relying on thermoelectric chips or circulatory liquid cooling systems for cooling or heat conduction, the light-weighted, soft robotic clothing can effectively regulate temperature itself without any energy consumption.

Dr Shou said, “Wearing heavy firefighting gear can feel extremely stifling. When firefighters exit a fire scene and remove their gear, they are sometimes drained nearly a pound of sweat from their boots [sic]. This has motivated me to develop a novel suit capable of adapting to various environmental temperatures while maintaining excellent breathability. Our soft robotic clothing can seamlessly adapt to different seasons and climates, multiple working and living conditions, and transitions between indoor and outdoor environments to help users experience constant thermal comfort under intense heat.”

Looking forward, Dr Shou finds the innovation to have a wide range of potential applications, from activewear, winter jackets, healthcare apparel and outdoor gear, to sustainable textile-based insulation for construction and buildings, contributing to energy-saving efforts. Supported by the Innovation and Technology Commission and the Hong Kong Research Institute of Textiles and Apparel, Dr Shou and his team have also extended the thermo-adaptive concept to develop inflatable, breathable jackets and warm clothing. This soft robotic clothing is suitable for low-temperature environments or sudden temperature drops to aid those who are stranded in the wilderness to maintain normal body temperature.

Here’s a link to and a citation for the paper,

Soft Robotic Textiles for Adaptive Personal Thermal Management by Xiaohui Zhang, Zhaokun Wang, Guanghan Huang, Xujiang Chao, Lin Ye, Jintu Fan, Dahua Shou. Volume 11, Issue 21 June 5, 2024 2309605 First published online: 26 March 2024 DOI: https://doi.org/10.1002/advs.202309605

This paper is open access.

‘Jelly’ batteries

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Caption: Researchers have developed soft, stretchable ‘jelly batteries’ that could be used for wearable devices or soft robotics, or even implanted in the brain to deliver drugs or treat conditions such as epilepsy. Credit: University of Cambridge

A July 18, 2024 news item on Nanowerk announces bioinspried stretchy batteries from the University of Cambridge,

Researchers have developed soft, stretchable ‘jelly batteries’ that could be used for wearable devices or soft robotics, or even implanted in the brain to deliver drugs or treat conditions such as epilepsy.

The researchers, from the University of Cambridge, took their inspiration from electric eels, which stun their prey with modified muscle cells called electrocytes.

Like electrocytes, the jelly-like materials developed by the Cambridge researchers have a layered structure, like sticky Lego, that makes them capable of delivering an electric current.

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A July 17, 2024 University of Cambridge press release (also on EurekAlert), which originated the news item, offers more details,

The self-healing jelly batteries can stretch to over ten times their original length without affecting their conductivity – the first time that such stretchability and conductivity has been combined in a single material. The results are reported in the journal Science Advances.

The jelly batteries are made from hydrogels: 3D networks of polymers that contain over 60% water. The polymers are held together by reversible on/off interactions that control the jelly’s mechanical properties.

The ability to precisely control mechanical properties and mimic the characteristics of human tissue makes hydrogels ideal candidates for soft robotics and bioelectronics; however, they need to be both conductive and stretchy for such applications.

“It’s difficult to design a material that is both highly stretchable and highly conductive, since those two properties are normally at odds with one another,” said first author Stephen O’Neill, from Cambridge’s Yusuf Hamied Department of Chemistry. “Typically, conductivity decreases when a material is stretched.”

“Normally, hydrogels are made of polymers that have a neutral charge, but if we charge them, they can become conductive,” said co-author Dr Jade McCune, also from the Department of Chemistry. “And by changing the salt component of each gel, we can make them sticky and squish them together in multiple layers, so we can build up a larger energy potential.”

Conventional electronics use rigid metallic materials with electrons as charge carriers, while the jelly batteries use ions to carry charge, like electric eels.

The hydrogels stick strongly to each other because of reversible bonds that can form between the different layers, using barrel-shaped molecules called cucurbiturils that are like molecular handcuffs. The strong adhesion between layers provided by the molecular handcuffs allows for the jelly batteries to be stretched, without the layers coming apart and crucially, without any loss of conductivity.

The properties of the jelly batteries make them promising for future use in biomedical implants, since they are soft and mould to human tissue. “We can customise the mechanical properties of the hydrogels so they match human tissue,” said Professor Oren Scherman, Director of the Melville Laboratory for Polymer Synthesis, who led the research in collaboration with Professor George Malliaras from the Department of Engineering. “Since they contain no rigid components such as metal, a hydrogel implant would be much less likely to be rejected by the body or cause the build-up of scar tissue.”

In addition to their softness, the hydrogels are also surprisingly tough. They can withstand being squashed without permanently losing their original shape, and can self-heal when damaged.

The researchers are planning future experiments to test the hydrogels in living organisms to assess their suitability for a range of medical applications.

The research was funded by the European Research Council and the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI). Oren Scherman is a Fellow of Jesus College, Cambridge.

Here’s a link to and a citation for the paper,

Highly stretchable dynamic hydrogels for soft multilayer electronics by Stephen J. K. O’Neill, Zehuan Huang, Xiaoyi Chen, Renata L. Sala, Jade A. McCune, George G. Malliaras, and Oren A. Scherman. Science Advances 17 Jul 2024 Vol 10, Issue 29 DOI: 10.1126/sciadv.adn5142

This paper appears to be open access.

Electricity (electrodeposition) could help fight coastal (beach) erosion

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I live in a coastal region and a few months ago our local municipal voted down an initiative that included some mitigation for beach erosion. So, this research caught my eye.

Caption: An artistic impression of how electricity could be used to strengthen coastlines. Credit: Northwestern University

An August 22, 2024 news item on phys.org announces an unexpected approach to dealing with coastal erosion,

New research from Northwestern University has systematically proven that a mild zap of electricity can strengthen a marine coastline for generations—greatly reducing the threat of erosion in the face of climate change and rising sea levels.

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An August 22, 2024 Northwestern University news release (received via email and also found on EurekAlert) by Amanda Morris, which originated the news item, delves further into the topic, Note: Links have been removed,

In the new study, researchers took inspiration from clams, mussels and other shell-dwelling sea life, which use dissolved minerals in seawater to build their shells.

Similarly, the researchers leveraged the same naturally occurring, dissolved minerals to form a natural cement between sea-soaked grains of sand. But, instead of using metabolic energy like mollusks do, the researchers used electrical energy to spur the chemical reaction.

In laboratory experiments, a mild electrical current instantaneously changed the structure of marine sand, transforming it into a rock-like, immoveable solid. The researchers are hopeful this strategy could offer a lasting, inexpensive and sustainable solution for strengthening global coastlines.

The study will be published on Thursday (Aug. 22 [2024]) in the journal Communications Earth and the Environment, a journal published by Nature Portfolio.

“Over 40% of the world’s population lives in coastal areas,” said Northwestern’s Alessandro Rotta Loria, who led the study. “Because of climate change and sea-level rise, erosion is an enormous threat to these communities. Through the disintegration of infrastructure and loss of land, erosion causes billions of dollars in damage per year worldwide. Current approaches to mitigate erosion involve building protection structures or injecting external binders into the subsurface.

“My aim was to develop an approach capable of changing the status quo in coastal protection — one that didn’t require the construction of protection structures and could cement marine substrates without using actual cement. By applying a mild electric stimulation to marine soils, we systematically and mechanistically proved that it is possible to cement them by turning naturally dissolved minerals in seawater into solid mineral binders — a natural cement.”

Rotta Loria is the Louis Berger Assistant Professor of Civil and Environmental Engineering at Northwestern’s McCormick School of Engineering. Andony Landivar Macias, a former Ph.D. candidate in Rotta Loria’s laboratory, is the paper’s first author. Steven Jacobsen, a mineralogist and professor of Earth and planetary sciences in Northwestern’s Weinberg College of Arts and Sciences, also co-authored the study.

Sea walls, too, erode

From intensifying rainstorms to rising sea levels, climate change has created conditions that are gradually eroding coastlines. According to a 2020 study by the European commission’s Joint Research Centre, nearly 26% of the Earth’s beaches will be washed away by the end of this century.

To mitigate this issue, communities have implemented two main approaches: building protection structures and barriers, such as sea walls, or injecting cement into the ground to strengthen marine substrates, widely consisting of sand. But multiple problems accompany these strategies. Not only are these conventional methods extremely expensive, they also do not last.

“Sea walls, too, suffer from erosion,” Rotta Loria said. “So, over time, the sand beneath these walls erodes, and the walls can eventually collapse. Oftentimes, protection structures are made of big stones, which cost millions of dollars per mile. However, the sand beneath them can essentially liquify because of a number of environmental stressors, and these big rocks are swallowed by the ground beneath them.

“Injecting cement and other binders into the ground has a number of irreversible environmental drawbacks. It also typically requires high pressures and significant interconnected amounts of energy.”

Turning ions into glue

To bypass these issues, Rotta Loria and his team developed a simpler technique, inspired by coral and mollusks. Seawater naturally contains a myriad of ions and dissolved minerals. When a mild electrical current (2 to 3 volts) is applied to the water, it triggers chemical reactions. This converts some of these constituents into solid calcium carbonate — the same mineral mollusks use to build their shells. Likewise, with a slightly higher voltage (4 volts), these constituents can be predominantly converted into magnesium hydroxide and hydromagnesite, a ubiquitous mineral found in various stones.

When these minerals coalesce in the presence of sand, they act like a glue, binding the sand particles together. In the laboratory, the process also worked with all types of sands — from common silica and calcareous sands to iron sands, which are often found near volcanoes.

“After being treated, the sand looks like a rock,” Rotta Loria said. “It is still and solid, instead of granular and incohesive. The minerals themselves are much stronger than concrete, so the resulting sand could become as strong and solid as a sea wall.”

While the minerals form instantaneously after the current is applied, longer electric stimulations garner more substantial results. “We have noticed remarkable outcomes from just a few days of stimulations,” Rotta Loria said. “Then, the treated sand should stay in place, without needing further interventions.”

Ecofriendly and reversible

Rotta Loria predicts the treated sand should keep its durability, protecting coastlines and property for decades.

Rotta Loria also says there is no need to worry negative effects on sea life. The voltages used in the process are too mild to feel. Other researchers have used similar processes to strengthen undersea structures or even restore coral reefs. In those scenarios, no sea critters were harmed.

And, if communities decide they no longer want the solidified sand, Rotta Loria has a solution for that, too, as the process is completely reversible. When the battery’s anode and cathode electrodes are switched, the electricity dissolves the minerals — effectively undoing the process.

“The minerals form because we are locally raising the pH of the seawater around cathodic interfaces,” Rotta Loria said. “If you switch the anode with the cathode, then localized reductions in pH are involved, which dissolve the previously precipitated minerals.”

Competitive cost, countless applications

The process offers an inexpensive alternative to conventional methods. After crunching the numbers, Rotta Loria’s team estimates that his process costs just $3 to $6 per cubic meter of electrically cemented ground. More established, comparable methods, which use binders to adhere and strengthen sand, cost up to $70 for the same unit volume.

Research in Rotta Loria’s lab shows this approach also can heal cracked structures made of reinforced concrete. Much of the existing shoreside infrastructure is made of reinforced concrete, which disintegrates due to complex effects caused by sea-level rise, erosion and extreme weather. And if these structures crack, the new approach bypasses the need to fully rebuild the infrastructure. Instead, one pulse of electricity can heal potentially destructive cracks.

“The applications of this approach are countless,” Rotta Loria said. “We can use it to strengthen the seabed beneath sea walls or stabilize sand dunes and retain unstable soil slopes. We could also use it to strengthen protection structures, marine foundations and so many other things. There are many ways to apply this to protect coastal areas.”

Next, Rotta Loria’s team plans to test the technique outside of the laboratory and on the beach.

The study, “Electrodeposition of calcareous cement from seawater in marine silica sands,” was supported by the Army Research Office (grant number W911NF2210291) and Northwestern’s Center for Engineering Sustainability and Resilience.

Here’s a link to and a citation for the paper,

Electrodeposition of calcareous cement from seawater in marine silica sands by Andony Landivar Macias, Steven D. Jacobsen & Alessandro F. Rotta Loria. Communications Earth & Environment volume 5, Article number: 442 (2024) DOI: https://doi.org/10.1038/s43247-024-01604-3 Published: 22 August 2024

This paper is open access.

Peptide-based hydrogels for faster healing from research team at the University of Ottawa

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While this research team was heavily dominated by researchers from the University of Ottawa, there were two members associated with the University of Talca (Universidad de Talca; located in Chile), two members associated with the University of Montreal (Université de Montréal), and one member with McGill University (located in Montréal).

Now for these special hydrogels, from a May 13, 2024 University of Ottawa news release (also on EurekAlert) by David McFadden, Note: Links have been removed,

Combining biomedical finesse and nature-inspired engineering, a uOttawa-led team of scientists have created a jelly-like material that shows great potential for on-the-spot repair to a remarkable range of damaged organs and tissues in the human body.

Cutting-edge research co-led by uOttawa Faculty of Medicine  Associate Professor Dr. Emilio I. Alarcón could eventually impact millions of lives with peptide-based hydrogels that will close skin wounds, deliver therapeutics to damaged heart muscle, as well as reshape and heal injured corneas.

“We are using peptides to fabricate therapeutic solutions. The team is drawing inspiration from nature to develop simple solutions for wound closure and tissue repair,” says Dr. Alarcón, a scientist and director at the BioEngineering and Therapeutic Solutions (BEaTS) group at the University of Ottawa Heart Institutek whose innovative research work is focused on developing new materials with capabilities for tissue regeneration.

Peptides are molecules in living organisms and hydrogels are a water-based material with a gelatinous texture that have proven useful in therapeutics.

The approach used in the study –  just published in Advanced Functional Materials and co-led by Dr. Erik Suuronen & Dr. Marc Ruel – is unique. Most hydrogels explored in tissue engineering are animal-derived and protein-based materials, but the biomaterial created by the collaborative team is supercharged by engineered peptides. This makes it more clinically translatable.

Dr. Ruel, a full professor in the uOttawa Faculty of Medicine’s Department of Cellular and Molecular Medicine and the endowed chair of research in the Division of Cardiac Surgery at the University of Ottawa Heart Institute, says the study’s insights could be a game changer.

“Despite millennia of evolution, the human response to wound healing still remains imperfect,” Dr. Ruel says. “We see maladapted scarring in everything from skin incisions to eye injuries, to heart repair after a myocardial infarction. Drs. Alarcón, Suuronen, and the rest of our team have focused on this problem for almost two decades. The publication by Dr. Alarcón in Advanced Functional Materials reveals a novel way to make wound healing, organ healing, and even basic scarring after surgery much more therapeutically modulatable and, therefore, optimizable for human health.”

Indeed, the ability to modulate the peptide-based biomaterial is key. The uOttawa-led team’s hydrogels are designed to be customizable, making the durable material adaptable for use in a surprising range of tissues. Essentially, the two-component recipe could be adjusted to ramp up adhesivity or dial down other components depending on the part of the body needing repair.

“We were in fact very surprised by the range of applications our materials can achieve,” says Dr. Alarcón. “Our technology offers an integrated solution that is customizable depending on the targeted tissue.”

Dr. Alarcón says that not only does the study’s data suggest that the therapeutic action of the biomimetic hydrogels are highly effective, but its application is far simpler and cost-effective than other regenerative approaches.

The materials are engineered in a low-cost and scalable manner – hugely important qualities for any number of major biomedical applications. The team also devised a rapid-screening system that allowed them to significantly slash the design costs and testing timespans.

“This significant reduction in cost and time not only makes our material more economically viable but also accelerates its potential for clinical use,” Dr. Alarcón says.

What are next steps for the talent-rich research team? They will conduct large animal tests in preparation for tests in human subjects. So far, heart and skin tests were conducted with rodents, and the cornea work was done ex vivo.

Part of the work for this study was funded by the uOttawa Faculty of Medicine’s  “Path to Patenting & Pre-Commercialization” (3P),  an innovation-focused approach to provide our community’s top-flight researchers with the assistance needed to bring their most promising breakthroughs to the wider world.

Here’s a link to and a citation for the paper,

Multipurpose On-the-Spot Peptide-Based Hydrogels for Skin, Cornea, and Heart Repair by Alex Ross, Xixi Guo, German A. Mercado Salazar, Sergio David Garcia Schejtman, Jinane El-Hage, Maxime Comtois-Bona, Aidan Macadam, Irene Guzman-Soto, Hiroki Takaya, Kevin Hu, Bryan Liu, Ryan Tu, Bilal Siddiqi, Erica Anderson, Marcelo Muñoz, Patricio Briones-Rebolledo, Tianqin Ning, May Griffith, Benjamin Rotsein, Horacio Poblete, Jianyu Li, Marc Ruel, Erik J. Suuronen, Emilio I. Alarcon. Advanced Functional Materials DOI: https://doi.org/10.1002/adfm.202402564 First published: 23 April 2024

This paper is open access.

Bionic jellyfish for deep ocean exploration

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This research may be a little disturbing for animal lovers as it involves conjoining a jellyfish (or sea jelly) and a robotic device. That said, a February 29, 2024 news item on ScienceDaily highlights new research into the oceanic depths,

Jellyfish can’t do much besides swim, sting, eat, and breed. They don’t even have brains. Yet, these simple creatures can easily journey to the depths of the oceans in a way that humans, despite all our sophistication, cannot.

But what if humans could have jellyfish explore the oceans on our behalf, reporting back what they find? New research conducted at Caltech [California Institute of Technology] aims to make that a reality through the creation of what researchers call biohybrid robotic jellyfish. These creatures, which can be thought of as ocean-going cyborgs, augment jellyfish with electronics that enhance their swimming and a prosthetic “hat” that can carry a small payload while also making the jellyfish swim in a more streamlined manner.

…

The researchers describe their work and provide recordings of the jellyfish,

A February 28, 2024 California Institute of Technology (Caltech) news release (also on EurekAlert) by Emily Velasco, which originated the news item, provides more detail,

The work, published in the journal Bioinspiration & Biomimetics, was conducted in the lab of John Dabiri (MS ’03, PhD ’05), the Centennial Professor of Aeronautics and Mechanical Engineering, and builds on his previous work augmenting jellyfish. Dabiri’s goal with this research is to use jellyfish as robotic data-gatherers, sending them into the oceans to collect information about temperature, salinity, and oxygen levels, all of which are affected by Earth’s changing climate.

“It’s well known that the ocean is critical for determining our present and future climate on land, and yet, we still know surprisingly little about the ocean, especially away from the surface,” Dabiri says. “Our goal is to finally move that needle by taking an unconventional approach inspired by one of the few animals that already successfully explores the entire ocean.”

Throughout his career, Dabiri has looked to the natural world, jellyfish included, for inspiration in solving engineering challenges. This work began with early attempts by Dabiri’s lab to develop a mechanical robot that swam like jellyfish, which have the most efficient method for traveling through water of any living creature. Though his research team succeeded in creating such a robot, that robot was never able to swim as efficiently as a real jellyfish. At that point, Dabiri asked himself, why not just work with jellyfish themselves?

“Jellyfish are the original ocean explorers, reaching its deepest corners and thriving just as well in tropical or polar waters,” Dabiri says. “Since they don’t have a brain or the ability to sense pain, we’ve been able to collaborate with bioethicists to develop this biohybrid robotic application in a way that’s ethically principled.”

Previously, Dabiri’s lab implanted jellyfish with a kind of electronic pacemaker that controls the speed at which they swim. In doing so, they found that if they made jellyfish swim faster than the leisurely pace they normally keep, the animals became even more efficient. A jellyfish swimming three times faster than it normally would uses only twice as much energy.

This time, the research team went a step further, adding what they call a forebody to the jellies. These forebodies are like hats that sit atop the jellyfish’s bell (the mushroom-shaped part of the animal). The devices were designed by graduate student and lead author Simon Anuszczyk (MS ’22), who aimed to make the jellyfish more streamlined while also providing a place where sensors and other electronics can be carried.

“Much like the pointed end of an arrow, we designed 3D-printed forebodies to streamline the bell of the jellyfish robot, reduce drag, and increase swimming performance,” Anuszczyk says. “At the same time, we experimented with 3D printing until we were able to carefully balance the buoyancy and keep the jellyfish swimming vertically.”

To test the augmented jellies’ swimming abilities, Dabiri’s lab undertook the construction of a massive vertical aquarium inside Caltech’s Guggenheim Laboratory. Dabiri explains that the three-story tank is tall, rather than wide, because researchers want to gather data on oceanic conditions far below the surface.

“In the ocean, the round trip from the surface down to several thousand meters will take a few days for the jellyfish, so we wanted to develop a facility to study that process in the lab,” Dabiri says. “Our vertical tank lets the animals swim against a flowing vertical current, like a treadmill for swimmers. We expect the unique scale of the facility—probably the first vertical water treadmill of its kind—to be useful for a variety of other basic and applied research questions.”

Swim tests conducted in the tank show that a jellyfish equipped with a combination of the swimming pacemaker and forebody can swim up to 4.5 times faster than an all-natural jelly while carrying a payload. The total cost is about $20 per jellyfish, Dabiri says, which makes biohybrid jellies an attractive alternative to renting a research vessel that can cost more than $50,000 a day to run.

“By using the jellyfish’s natural capacity to withstand extreme pressures in the deep ocean and their ability to power themselves by feeding, our engineering challenge is a lot more manageable,” Dabiri adds. “We still need to design the sensor package to withstand the same crushing pressures, but that device is smaller than a softball, making it much easier to design than a full submarine vehicle operating at those depths.

“I’m really excited to see what we can learn by simply observing these parts of the ocean for the very first time,” he adds.

Dabiri says future work may focus on further enhancing the bionic jellies’ abilities. Right now, they can only be made to swim faster in a straight line, such as the vertical paths being designed for deep ocean measurement. But further research may also make them steerable, so they can be directed horizontally as well as vertically.

The paper describing the work, “Electromechanical enhancement of live jellyfish for ocean exploration,” appears in the XX issue of Bioinspiration & Biomimetics. Co-authors are Anuszczyk and Dabiri.

Funding for the research was provided by the National Science Foundation and the Charles Lee Powell Foundation.

Here’s a link to and a citation for the paper,

Electromechanical enhancement of live jellyfish for ocean exploration by Simon R Anuszczyk and John O Dabiri. Bioinspiration & Biomimetics, Volume 19, Number 2 DOI 10.1088/1748-3190/ad277f Published 28 February 2024

This paper is open access.

Bioinspired, biomimetic stimulation for the next generation of neuroprosthetics

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ETH researchers have developed a prosthetic leg that communicates with the brain via natural signals. (Photograph: Keystone) Courtesy: ETH Zurich

A February 21, 2024 ETH Zurich press release by Ori Schipper (also on EurekAlert) announces a ‘nature-inspired’ or bioinspired approach to neuroprosthetics,

Prostheses that connect to the nervous system have been available for several years. Now, researchers at ETH Zurich have found evidence that neuroprosthetics work better when they use signals that are inspired by nature.

In brief

*Neuroprostheses are electro-​mechanical devices that are connected to the nervous system. As yet, these are unable to provide natural communication with the brain. Instead, they often evoke artificial, unpleasant sensations, similar to a feeling of tingles over the skin.
*This paraesthesia might be caused by overstimulation of the nervous system. ETH Zurich researchers together with colleagues in Germany, Serbia and Russia have proposed that neuroprosthetics should transmit biomimetic signals that are easier for the brain to understand.
*These new findings are relevant to arm and leg prostheses as well as various other aids and devices, including spinal implants and electrodes for brain stimulation. 

A few years ago, a team of researchers working under Professor Stanisa Raspopovic at the ETH Zurich Neuroengineering Lab gained worldwide attention when they announced that their prosthetic legs had enabled amputees to feel sensations from this artificial body part for the first time. Unlike commercial leg prostheses, which simply provide amputees with stability and support, the ETH researchers’ prosthetic device was connected to the sciatic nerve in the test subjects’ thigh via implanted electrodes.

This electrical connection enabled the neuroprosthesis to communicate with the patient’s brain, for example relaying information on the constant changes in pressure detected on the sole of the prosthetic foot when walking. This gave the test subjects greater confidence in their prosthesis – and it enabled them to walk considerably faster on challenging terrains. “Our experimental leg prosthesis succeeded in evoking natural sensations. That’s something current neuroprostheses are mainly unable to do; instead, they mostly evoke artificial, unpleasant sensations,” Raspopovic says.

This is probably because today’s neuroprosthetics are using time-​constant electrical pulses to stimulate the nervous system. “That’s not only unnatural, but also inefficient,” Raspopovic says. In a recently published paper, he and his team used the example of their leg prostheses to highlight the benefits of using naturally inspired, biomimetic stimulation to develop the next generation of neuroprosthetics.

Model simulates activation of nerves in the sole

To generate these biomimetic signals, Natalija Katic – a doctoral student in Raspopovic’s research group – developed a computer model called FootSim. It is based on data collected by collaborators in Canada, who recorded the activity of natural receptors, named mechanoreceptors, in the sole of the foot while touching different points on the feet of volunteers with a vibrating rod.

The model simulates the dynamic behaviour of large numbers of mechanoreceptors in the sole of the foot and generates the neural signals that shoot up the nerves in the leg towards the brain – from the moment the heel strikes the ground and the weight of the body starts to shift forward to the outside of the foot until the toes push off the ground ready for the next step. “Thanks to this model, we can see how semsory receptors from the sole, and the connected nerves, behave during walking or running, which is experimentally impossible to measure” Katic says.

Information overload in the spinal cord

To assess how closely the biomimetic signals calculated by the model correspond to the signals emitted by real neurons, Giacomo Valle – a postdoc in Raspopovic’s research group – worked with colleagues in Germany, Serbia and Russia on experiments with cats, whose nervous system processes movement in a similar way to that of humans. The experiments took place in 2019 at the Pavlov Institute of Physiology in St. Petersburg and were carried out in accordance with the relevant European Union guidelines.

The researchers implanted electrodes, connecting some to the nerve in the leg and some to the spinal cord to discover how the signals are transmitted through the nervous system. When the researchers applied pressure to the bottom of the cat’s paw, thereby evoking the natural neural response that occurs when a cat takes a step, the peculiar pattern of activity recorded in the spinal cord did indeed resemble the patterns that were elicited in the spinal cord when the researchers stimulated the leg nerve with biomimetic signals.

By contrast, the conventional approach of time-​constant stimulation of the sciatic nerve in the cat’s thigh elicited a markedly different pattern of activation in the spinal cord. “This clearly shows that the commonly used stimulation methods cause the neural networks in the spine to be flooded with information,” Valle says. “This information overload could be the reason for the unpleasant sensations or paraesthesia reported by some users of neuroprosthetics,” Raspopovic adds.

Learning the language of the nervous system

In their clinical trial with leg amputees, the researchers were able to show that biomimetic stimulation is superior to time-​constant stimulation. Their work clearly demonstrated how the signals that mimicked nature produced better results: not only were the test subjects able to climb steps faster, they also made fewer mistakes in a task that required them to climb the same steps while spelling words backwards. “Biomimetic neurostimulation allows subjects to concentrate on other things while walking,” Raspopovic says, “so we concluded that this type of stimulation is more naturally processed and less taxing on the brain.”

Raspopovic, whose lab forms part of the ETH Institute of Robotics and Intelligent Systems, believes that these new findings are not only relevant to the limb prostheses he and his team have been working on for over half a decade. He argues that the need to move away from unnatural, time-​constant stimulation towards biomimetic signals also applies to a whole series of other aids and devices, including spinal implants and electrodes for brain stimulation. “We need to learn the language of the nervous system,” Raspopovic says. “Then we’ll be able to communicate with the brain in ways it really understands.”

Here’s a link to and a citation for the paper,

Biomimetic computer-to-brain communication enhancing naturalistic touch sensations via peripheral nerve stimulation by Giacomo Valle, Natalija Katic Secerovic, Dominic Eggemann, Oleg Gorskii, Natalia Pavlova, Francesco M. Petrini, Paul Cvancara, Thomas Stieglitz, Pavel Musienko, Marko Bumbasirevic & Stanisa Raspopovic. Nature Communications volume 15, Article number: 1151 (2024) DOI: https://doi.org/10.1038/s41467-024-45190-6 Published: 20 February 2024

This paper is open access.

It was a bit of a surprise to see mention of some Canadian collaborators with regard to the earlier work featuring FootSim, a computer model Here’s a link to and a citation to that paper, this version is housed at ETH Zurich,

Modeling foot sole cutaneous afferents: FootSim by Natalija Katic, Rodrigo Kazu Siqueira, Luke Cleland, Nicholas Strzalkowski, Leah Bent, Stanisa Raspopovic, and Hannes Saal. Originally published in: iScience 26(1), DOI https://doi.org/10.1016/j.isci.2022.105874 Publication date: 2023-01-20 Permanent link: https://doi.org/10.3929/ethz-b-000591102

This paper too is open access.