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Going small for big solutions: Sub-nanoparticle catalysts made from coinage elements as effective catalysts

Due to their small size, nanoparticles find varied applications in fields ranging from medicine to electronics. Their small size allows them a high reactivity and semiconducting property not found in the bulk states. Sub-nanoparticles (SNPs) have an extremely small diameter of around 1 nm, making them even smaller than nanoparticles. Almost all atoms of SNPs are available and exposed for reactions, and therefore, SNPs are expected to have extraordinary functions beyond the properties of nanoparticles, particularly as catalysts for industrial reactions. However, preparation of SNPs requires fine control of the size and composition of each particle on a sub-nanometer scale, making the application of conventional production methods near impossible.

To overcome this, researchers at the Tokyo Institute of Technology led by Dr. Takamasa Tsukamoto and Prof. Kimihisa Yamamoto previously developed the atom hybridization method (AHM) which surpasses the previous trials of SNP synthesis. Using this technique, it is possible to precisely control and diversely design the size and composition of the SNPs using a “macromolecular template” called phenylazomethine dendrimer. This improves their catalytic activity than the NP catalysts.

Now, in their latest study published in Angewandte Chemie International Edition, the team has taken their research one step further and has investigated the chemical reactivity of alloy SNPs obtained through the AHM. “We created monometallic, bimetallic, and trimetallic SNPs (containing one, combination of two, and combination of three metals respectively), all composed of coinage metal elements (copper, silver, and gold), and tested each to see how good of a catalyst each of them is,” reports Dr Tsukamoto. 

Unlike corresponding nanoparticles, the SNPs created were found to be stable and more effective. Moreover, SNPs showed a high catalytic performance even under the milder conditions, in direct contrast to conventional catalysts. Monometallic, bimetallic, and trimetallic SNPs demonstrated the formation of different products, and this hybridization or combination of metals seemed to show a higher turnover frequency (TOF). The trimetallic combination “Au4Ag8Cu16” showed the highest TOF because each metal element plays a unique role, and these effects work in concert to contribute to high reaction activity.

Furthermore, SNP selectively created hydroperoxide, which is a high-energy compound that cannot be normally obtained due to instability. Mild reactions without high temperature and pressure realized in SNP catalysts resulted in the stable formation of hydroperoxide by suppressing its decomposition.

When asked about the relevance of these findings, Prof Yamamoto states: “We demonstrate for the first time ever, that olefin hydroperoxygenation can been catalyzed under extremely mild conditions using metal particles in the quantum size range. The reactivity was significantly improved in the alloyed systems especially for the trimetallic combinations, which has not been studied previously.”

The team emphasized that because of the extreme miniaturization of the structures and the hybridization of different elements, the coinage metals acquired a high enough reactivity to catalyze the oxidation even under the mild condition. These findings will prove to be a pioneering key in the discovery of innovative sub-nanomaterials from a wide variety of elements and can solve energy crises and environmental problems in the years to come.

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When Dirac meets frustrated magnetism

The fields of condensed matter physics and material science are intimately linked because new physics is often discovered in materials with special arrangements of atoms. Crystals, which have repeating units of atoms in space, can have special patterns which result in exotic physical properties. Particularly exciting are materials which host multiple types of exotic properties because they give scientists the opportunity to study how those properties interact with and influence each other. The combinations can give rise to unexpected phenomena and fuel years of basic and technological research.

In a new study published in Science Advances this week, an international team of scientists from the USA, Columbia, Czech Republic, England, and led by Dr. Mazhar N. Ali at the Max Planck Institute of Microstructure Physics in Germany, has shown that a new material, KV3Sb5, has a never-seen-before combination of properties that results in one of the largest anomalous Hall effects (AHEs) ever observed; 15,500 siemens per centimeter at 2 Kelvin.

Discovered in the lab of co-author Prof. Tyrel McQueen at Johns Hopkins University, KV3Sb5 combines four properties into one material: Dirac physics, metallic frustrated magnetism, 2D exfoliability (like graphene), and chemical stability.

Dirac physics, in this context, relates to the fact that the electrons in KV3Sb5 aren’t just your normal run-of-the-mill electrons; they are moving extremely fast with very low effective mass. This means that they are acting “light-like”; their velocities are becoming comparable to the speed of light and they are behaving as though they have only a small fraction of the mass which they should have. This results in the material being highly metallic and was first shown in graphene about 15 years ago.

The “frustrated magnetism” arises when the magnetic moments in a material (imagine little bar magnets which try to turn each other and line up North to South when you bring them together) are arranged in special geometries, like triangular nets. This scenario can make it hard for the bar magnets to line up in way that they all cancel each other out and are stable. Materials exhibiting this property are rare, especially metallic ones. Most frustrated magnet materials are electrical insulators, meaning that their electrons are immobile. “Metallic frustrated magnets have been highly sought after for several decades. They have been predicted to house unconventional superconductivity, Majorana fermions, be useful for quantum computing, and more,” commented Dr. Ali.

Structurally, KV3Sb5 has a 2D, layered structure where triangular vanadium and antimony layers loosely stack on top of potassium layers. This allowed the authors to simply use tape to peel off a few layers (a.k.a. flakes) at a time. “This was very important because it allowed us to use electron-beam lithography (like photo-lithography which is used to make computer chips, but using electrons rather than photons) to make tiny devices out of the flakes and measure properties which people can’t easily measure in bulk.” remarked lead author Shuo-Ying Yang, from the Max Planck Institute of Microstructure Physics. “We were excited to find that the flakes were quite stable to the fabrication process, which makes it relatively easy to work with and explore lots of properties.”

Armed with this combination of properties, the team first chose to look for an anomalous Hall effect (AHE) in the material. This phenomenon is where electrons in a material with an applied electric field (but no magnetic field) can get deflected by 90 degrees by various mechanisms. “It had been theorized that metals with triangular spin arrangements could host a significant extrinsic effect, so it was a good place to start,” noted Yang. Using angle resolved photoelectron spectroscopy, microdevice fabrication, and a low temperature electronic property measurement system, Shuo-Ying and co-lead author Yaojia Wang (Max Planck Institute of Microstructure Physics) were able to observe one of the largest AHE’s ever seen.

The AHE can be broken into two general categories: intrinsic and extrinsic. “The intrinsic mechanism is like if a football player made a pass to their teammate by bending the ball, or electron, around some defenders (without it colliding with them),” explained Ali. “Extrinsic is like the ball bouncing off of a defender, or magnetic scattering center, and going to the side after the collision. Many extrinsically dominated materials have a random arrangement of defenders on the field, or magnetic scattering centers randomly diluted throughout the crystal. KV3Sb5 is special in that it has groups of 3 magnetic scattering centers arranged in a triangular net. In this scenario, the ball scatters off of the cluster of defenders, rather than a single one, and is more likely to go to the side than if just one was in the way.” This is essentially the theorized spin-cluster skew scattering AHE mechanism which was demonstrated by the authors in this material. “However the condition with which the incoming ball hits the cluster seems to matter; you or I kicking the ball isn’t the same as if, say, Christiano Ronaldo kicked the ball,” added Ali. “When Ronaldo kicks it, it is moving way faster and bounces off of the cluster with way more velocity, moving to the side faster than if just any average person had kicked it. This is, loosely speaking, the difference between the Dirac quasiparticles (Ronaldo) in this material vs normal electrons (average person) and is related to why we see such a large AHE,” Ali laughingly explained.

These results may also help scientists identify other materials with this combination of ingredients. “Importantly, the same physics governing this AHE could also drive a very large spin Hall effect (SHE) — where instead of generating an orthogonal charge current, an orthogonal spin current is generated,” remarked Wang. “This is important for next-generation computing technologies based on an electron’s spin rather than its charge.”

“This is a new playground material for us: metallic Dirac physics, frustrated magnetism, exfoliatable, and chemically stable all in one. There is a lot of opportunity to explore fun, weird phenomena, like unconventional superconductivity and more,” said Ali, excitedly.

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New cosmic magnetic field structures discovered in galaxy NGC 4217

Spiral galaxies such as our Milky Way can have sprawling magnetic fields. There are various theories about their formation, but so far the process is not well understood. An international research team has now analysed the magnetic field of the Milky Way-like galaxy NGC 4217 in detail on the basis of radio astronomical observations and has discovered as yet unknown magnetic field structures. The data suggest that star formation and star explosions, so-called supernovae, are responsible for the visible structures.

The team led by Dr. Yelena Stein from Ruhr-Universität Bochum, the Centre de Données astronomiques de Strasbourg and the Max Planck Institute for Radio Astronomy in Bonn together with US-American and Canadian colleagues, published their report in the journal Astronomy and Astrophysics, released online on 21 July 2020.

The analysed data had been compiled in the project “Continuum Halos in Nearby Galaxies,” where radio waves were utilised to measure 35 galaxies. “Galaxy NGC 4217 is of particular interest to us,” explains Yelena Stein, who began the study at the Chair of Astronomy at Ruhr-Universität Bochum under Professor Ralf-Jürgen Dettmar and who currently works at the Centre de Données astronomiques de Strasbourg. NGC 4217 is similar to the Milky Way and is only about 67 million light years away, which means relatively close to it, in the Ursa Major constellation. The researchers therefore hope to successfully transfer some of their findings to our home galaxy.

Magnetic fields and origins of star formation

When evaluating the data from NGC 4217, the researchers found several remarkable structures. The galaxy has an X-shaped magnetic field structure, which has also been observed in other galaxies, extending far outwards from the galaxy disk, namely over 20,000 light years.

In addition to the X-shape, the team found a helix structure and two large bubble structures, also called superbubbles. The latter originate from places where many massive stars explode as supernovae, but also where stars are formed that emit stellar winds in the process. Researchers therefore suspect a connection between these phenomena.

“It is fascinating that we discover unexpected phenomena in every galaxy whenever we use radio polarisation measurements,” points out Dr. Rainer Beck from the MPI for Radio Astronomy in Bonn, one of the authors of the study. “Here in NGC 4217, it is huge magnetic gas bubbles and a helix magnetic field that spirals upwards into the galaxy’s halo.”

The analysis moreover revealed large loop structures in the magnetic fields along the entire galaxy. “This has never been observed before,” explains Yelena Stein. “We suspect that the structures are caused by star formation, because at these points matter is ejected outward.”

Image shows magnetic field structures

For their analysis, the researchers combined different methods that enabled them to visualise the ordered and chaotic magnetic fields of the galaxy both along the line of sight and perpendicular to it. The result was a comprehensive image of the structures.

To optimise the results, Yelena Stein combined the data evaluated by means of radio astronomy with an image of NGC 4217 that was taken in the visible light range. . “Visualising the data was important to me,” stresses Stein. “Because when you think about galaxies, magnetic fields is not the first thing that comes to mind, although they can be gigantic and display unique structures. The image is supposed to shift the magnetic fields more into focus.”

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The lightest shielding material in the world

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic components or the transmission of signals. High-frequency electromagnetic fields can only be shielded with conductive shells that are closed on all sides. Often thin metal sheets or metallized foils are used for this purpose. However, for many applications such a shield is too heavy or too poorly adaptable to the given geometry. The ideal solution would be a light, flexible and durable material with extremely high shielding effectiveness.

Aerogels against electromagnetic radiation

A breakthrough in this area has now been achieved by a research team led by Zhihui Zeng and Gustav Nyström. The researchers are using nanofibers of cellulose as the basis for an aerogel, which is a light, highly porous material. Cellulose fibres are obtained from wood and, due to their chemical structure, enable a wide range of chemical modifications. They are therefore a highly popular research object. The crucial factor in the processing and modification of these cellulose nanofibres is to be able to produce certain microstructures in a defined way and to interpret the effects achieved. These relationships between structure and properties are the very field of research of Nyström’s team at Empa.

The researchers have succeeded in producing a composite of cellulose nanofibers and silver nanowires, and thereby created ultra-light fine structures which provide excellent shielding against electromagnetic radiation. The effect of the material is impressive: with a density of only 1.7 milligrams per cubic centimeter, the silver-reinforced cellulose aerogel achieves more than 40 dB shielding in the frequency range of high-resolution radar radiation (8 to 12 GHz) — in other words: Virtually all radiation in this frequency range is intercepted by the material.

Ice crystals control the shape

Not only the correct composition of cellulose and silver wires is decisive for the shielding effect, but also the pore structure of the material. Within the pores, the electromagnetic fields are reflected back and forth and additionally trigger electromagnetic fields in the composite material, which counteract the incident field. To create pores of optimum size and shape, the researchers pour the material into pre-cooled moulds and allow it to freeze out slowly. The growth of the ice crystals creates the optimum pore structure for damping the fields.

With this production method, the damping effect can even be specified in different spatial directions: If the material freezes out in the mould from bottom to top, the electromagnetic damping effect is weaker in the vertical direction. In the horizontal direction — i.e. perpendicular to the freezing direction — the damping effect is optimized. Shielding structures cast in this way are highly flexible: even after being bent back and forth a thousand times, the damping effect is practically the same as with the original material. The desired absorption can even be easily adjusted by adding more or less silver nanowires to the composite, as well as by the porosity of the cast aerogel and the thickness of the cast layer.

The lightest electromagnetic shield in the world

In another experiment, the researchers removed the silver nanowires from the composite material and connected their cellulose nanofibres with two-dimensional nanoplates of titanium carbide, which were produced using a special etching process. The nanoplates act like hard “bricks” that are joined together with flexible “mortar” made of cellulose fibers. This formulation was also frozen in cooled forms in a targeted manner. In relation to the weight of the material, no other material can achieve such shielding. This ranks the titanium carbide nanocellulose aerogel as by far the lightest electromagnetic shielding material in the world.

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3D Printing Industry

How 3D printing is being used in the field of urology

Since its inception in the 80s, 3D printing has managed to find itself in more industries and fields than we can count. One such area is urology – the medical field concerned with the urinary-tract system. A recent literature review published in BJU International covers the latest developments and accomplishments of researchers employing 3D printing […]

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New understanding of energy fluctuations in fluids

The Casimir Force is a well-known effect originating from the quantum fluctuation of electromagnetic fields in a vacuum. Now an international group of researchers have reported a counterpoint to that theory, adding to the understanding of energy fluctuations within fluids.

Ultimately, said Rodolfo Ostilla-Mónico, the goal is to apply the findings to better understand the collective behavior of bacteria and other organisms. Ostilla-Mónico, assistant professor of mechanical engineering at the University of Houston, is co-corresponding author of a paper describing the discovery, published Friday in Science Advances.

The customary effect of the Casimir Force is well understood, Ostilla-Mónico said. “This is an analog to this force in a non-quantum system. We are especially interested in the biological implications.”

In addition to Ostilla-Mónico, researchers involved in the project include Daniel Putt, a graduate student at UH; Vamsi Spandan from Harvard University; and Alpha A. Lee of the University of Cambridge.

The work builds upon the Casimir Force, one of the governing principles of physics which describes a force arising from the unending electromagnetic waves found in a vacuum. It suggests that a vacuum, rather than being empty, is filled with energy, and this is demonstrated by measuring the force as two plates placed in the vacuum are attracted and move closer to one another because they confine the fluctuations of the electromagnetic field. Dutch physicist Hendrick Casimir first predicted the effect in 1948.

The current work similarly focused on the study of fluctuation-induced force between two plates; in this case the plates were immersed in isotropic turbulence, a scenario in which turbulent fluctuations are the same in all directions. It was designed to illustrate how hydrodynamic turbulence generates force between objects even when the flow has no preferred direction.

The work, the researchers wrote, “sheds light on how length scale-dependent distributions of energy and high-intensity vortex structures determine Casimir forces.”

Ostilla-Mónico said they were able to quantify that Casimir forces depend on specific parameters, including turbulence and positioning of the plates.

The findings have implications for micro and nanomanufacturing, but Ostilla-Mónico said the work grew out of the researchers’ interest in learning more about the behavior of bacteria. Bacteria are more complex to study, even computationally, but they determined that the study of turbulence would offer some parallels, because both continuously consume energy and generate similar flow fields.

“Turbulence needs energy to keep going,” he said. “Bacteria need to be constantly fed in order to keep moving.”

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Stimulating resonance with two very different forces

Widely studied in many different fields, ‘nonlinear’ systems can display excessively dramatic responses when the forces which cause them to vibrate are changed. Some of these systems are sensitive to changes in the very parameters which define their driving forces, and can be well described using mathematical equations. These ‘parametric’ oscillators have been widely researched in the past, but so far, few studies have investigated how they will respond to multiple driving forces. In new research published in EPJ B, Dhruba Banerjee and colleagues at Jadavpur University in Kolkata explore this case in detail for the first time. They show that some parametric oscillators can be made to resonate when tuned by a high driving frequency to match a separate, far lower frequency.

Since nonlinear oscillators can be found across a wide array of fields, from quantum mechanics to climate modelling, the discovery could enable researchers from many different backgrounds to better understand the systems they work with. In their study, Banerjee’s team used both simulations and experiments to explore the behaviours of ‘bistable’ oscillators, which can flip between two stable states of vibration. To do this, they subjected a bistable parametric system to two very different driving frequencies: one high, the other far lower.

Banerjee and colleagues made their calculations using ‘perturbation theory’, which finds approximate solutions to complex problems, starting from exact solutions to similar yet simpler problems. Through this technique, they showed that as the strength of a bistable parametric system’s high-frequency driving force is varied, its mathematically predictable, nonlinear response to a separate, low-frequency driving force varies in turn. Importantly, this means that the higher frequency’s strength can be tuned so that the oscillator’s frequency matches that of the low frequency driving force, causing it to resonate. The discovery could open up new opportunities for future studies of how nonlinear oscillators respond in a wide range of situations.

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Bizarre worlds orbiting a black hole?

Theoreticians in two different fields defied the common knowledge that planets orbit stars like the Sun. They proposed the possibility of thousands of planets around a supermassive black hole.

“With the right conditions, planets could be formed even in harsh environments, such as around a black hole,” says Keiichi Wada, a professor at Kagoshima University researching active galactic nuclei which are luminous objects energized by black holes.

According to the latest theories, planets are formed from fluffy dust aggregates in a protoplanetary disk around a young star. But young stars are not the only objects that possess dust disks. In a novel approach, the researchers focused on heavy disks around supermassive black holes in the nuclei of galaxies.

“Our calculations show that tens of thousands of planets with 10 times the mass of the Earth could be formed around 10 light-years from a black hole,” says Eiichiro Kokubo, a professor at the National Astronomical Observatory of Japan who studies planet formation. “Around black holes there might exist planetary systems of astonishing scale.”

Some supermassive black holes have large amounts of matter around them in the form of a heavy, dense disk. A disk can contain as much as a hundred thousand times the mass of the Sun worth of dust. This is a billion times the dust mass of a protoplanetary disk.

In a low temperature region of a protoplanetary disk, dust grains with ice mantles stick together and evolve into fluffy aggregates. A dust disk around a black hole is so dense that the intense radiation from the central region is blocked and low temperature regions are formed. The researchers applied the planet formation theory to circumnuclear disks and found that planets could be formed in several hundred million years.

Currently there are no techniques to detect these planets around black holes. However, the researchers expect this study to open a new field of astronomy.

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Intuitive virtual reality: Bimodal ‘electronic skin’ developed

Through the crafty use of magnetic fields, scientists from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the Johannes Kepler University in Linz have developed the first electronic sensor that can simultaneously process both touchless and tactile stimuli. Prior attempts have so far failed to combine these functions on a single device due to overlapping signals of the various stimuli. As the sensor is readily applied to the human skin, it could provide a seamless interactive platform for virtual and augmented reality scenarios. The researchers have published their results in the scientific journal Nature Communications.

The largest human organ — the skin — is likely the most functionally versatile part of the body. It is not only able to differentiate between the most varied stimuli within seconds, but it can also classify the intensity of signals over a broad range. A research team led by Dr. Denys Makarov from HZDR’s Institute of Ion Beam Physics and Materials Research as well the Soft Electronics Laboratory led by Prof. Martin Kaltenbrunner at Linz University have managed to produce an electronic counterpart with similar characteristics. According to the scientists, their new sensor could massively simplify the interplay between humans and machines, as Denys Makarov explains: “Applications in virtual reality are becoming increasingly more complex. We therefore need devices which can process and discriminate multiple interaction modes.”

The current systems, however, work either by only registering physical touch or by tracking objects in a touchless manner. Both interaction pathways have now been combined for the first time on the sensor, which has been termed a “magnetic microelectromechanical system” (m-MEMS) by the scientists. “Our sensor processes the electrical signals of the touchless and the tactile interactions in different regions,” says the publication’s first author Dr. Jin Ge from HZDR, adding, “and in this way, it can differentiate the stimuli’s origin in real time and suppress disturbing influences from other sources.” The foundation for this work is the unusual design the scientists worked out.

Flexibility on all surfaces

On a thin polymer film, they first fabricated a magnetic sensor, which relies on what is known as the Giant Magneto Resistance (GMR). This film in turn was sealed by a silicon-based polymer layer (polydimethylsiloxane) containing a round cavity designed to be precisely aligned with the sensor. Inside this void, the researchers integrated a flexible permanent magnet with pyramid-like tips protruding from its surface. “The result is rather more reminiscent of cling film with optical embellishments,” comments Makarov. “But this is precisely one of our sensor’s strengths.” This is how it remains so exceptionally flexible: it fits all environments perfectly. Even under curved conditions, it works without losing its functionality. The sensor can thus very easily be placed, for example, on the fingertip.

It is precisely in this manner that the scientists tested their development. Jin Ge elaborates: “On the leaf of a daisy we attached a permanent magnet, whose magnetic field points in the opposite direction of the magnet attached to our platform.” As the finger now approaches this external magnetic field, the electrical resistance of the GMR sensor changes: it drops. This occurs until the point when the finger actually touches the leaf. At this moment, it rises abruptly because the built-in permanent magnet is pressed closer to the GMR sensor and thus superimposes the external magnetic field. “This is how our m-MEMS platform can register a clear shift from touchless to tactile interaction in seconds,” says Jin Ge.

Click instead of click, click, click

This allows the sensor to selectively control both physical and virtual objects, as one of the experiments conducted by the team demonstrates: on a glass plate with which they furnished a permanent magnet, the physicists projected virtual buttons that manipulate real conditions, such as the room temperature or brightness. Using a finger on which the “electronic skin” had been applied, the scientists could first select the desired virtual function touchless through interaction with the permanent magnet. As soon as the finger touched the plate, the m-MEMS platform switched automatically to the tactile interaction mode. Light or heavy pressure could then be used, for example, to lower or increase the room temperature accordingly.

The researchers cut down an activity that had previously required several interactions to merely one. “This may sound like a small step at first,” says Martin Kaltenbrunner. “In the long-term, however, a better interface between humans and machines can be built on this foundation.” This “electronic skin” — in addition to virtual reality spaces — could also be used, for example, in sterile environments. Surgeons could use the sensors to handle medical equipment without touching it during a procedure, which would reduce the danger of contamination.

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Intelligent, shape-morphing, self-healing material for soft robotics

Advances in the fields of soft robotics, wearable technologies, and human/machine interfaces require a new class of stretchable materials that can change shape adaptively while relying only on portable electronics for power. Researchers at Carnegie Mellon University have developed such a material that exhibits a unique combination of high electrical and thermal conductivity with actuation capabilities that are unlike any other soft composite.

In findings published in Proceedings of the National Academy of Sciences this week, the researchers report on this intelligent new material that can adapt its shape in response to its environment. The paper is titled “A multifunctional shape-morphing elastomer with liquid metal inclusions.”

It is not only thermally and electrically conductive, it is also intelligent,” said Carmel Majidi, an associate professor of mechanical engineering who directs the Soft Machines Lab at Carnegie Mellon. “Just like a human recoils when touching something hot or sharp, the material senses, processes, and responds to its environment without any external hardware. Because it has neural-like electrical pathways, it is one step closer to artificial nervous tissue.”

Majidi is a pioneer in developing new classes of materials for use in soft matter engineering and soft robotics. His research team has previously created advanced material architectures using deformable liquid metal micro- and nano-droplets of gallium indium. This is the first time that his lab has combined this technique with liquid crystal elastomers (LCEs), a type of shape-morphing rubber. Majidi and his research team collaborated with LCE expert Taylor Ware, a professor of bioengineering at the University of Texas, Dallas, and his graduate student, Cedric Ambulo.

LCEs are like liquid crystals used in flat-panel displays but linked together like rubber. Because they move when they are exposed to heat, they hold promising functionality as a shape-morphing material; unfortunately, they lack the electrical and thermal conductivity needed for shape memory activation. Although rigid fillers can be incorporated to enhance conductivity, these cause the mechanical properties and the shape-morphing capabilities of LCEs to degrade. The researchers overcame these challenges by combining the liquid metal gallium indium with the LCEs to create a soft, stretchable composite with unprecedented multifunctionality.

Another key feature of the material is its resilience and response to significant damage.

“We observed both electrical self-healing and damage detection capabilities for this composite, but the damage detection went one step further than previous liquid metal composites,” explained Michael Ford, a postdoctoral research associate in the Soft Machines Lab and the lead author of the study. “Since the damage creates new conductive traces that can activate shape-morphing, the composite uniquely responds to damage.”

The material’s high electrical conductivity allows the composite to interface with traditional electronics, respond dynamically to touch, and change shape reversibly. It could be used in any application that requires stretchable electronics: healthcare, clothing, wearable computing, assistance devices and robots, and space travel.

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