The University of Nebraska-Lincoln engineering team has made significant strides in developing soft robotics and wearable systems inspired by human and plant skin’s ability to self-heal injuries. Led by engineer Eric Markvicka, the team presented a groundbreaking paper at the IEEE International Conference on Robotics and Automation that showcased their innovative approach to creating an intelligent, self-healing artificial muscle.

The team’s strategy overcomes the long-standing problem of replicating traditional rigid systems using soft materials and incorporating nature-inspired design principles. Their multi-layer architecture enables the system to identify damage, pinpoint its location, and autonomously initiate a self-repair mechanism – all without external intervention.

The “muscle” or actuator features three layers: a damage detection layer composed of liquid metal microdroplets embedded in silicone elastomer, a self-healing component that uses thermoplastic elastomer to seal the wound, and an actuation layer that kick-starts the muscle’s motion when pressurized with water.

To begin the process, the team induces monitoring currents across the damage detection layer, which triggers formation of an electrical network between traces. Puncture or pressure damage causes this network to form, allowing the system to recognize and respond to the damage.

The next step is using electromigration – a phenomenon traditionally viewed as a hindrance in metallic circuits – to erase the newly formed electrical footprint. By further ramping up the current, the team can induce electromigration and thermal failure mechanisms that reset the damage detection network, effectively completing one cycle of damage and repair.

This breakthrough has far-reaching implications for various industries, particularly in agricultural states where robotics systems frequently encounter sharp objects. It could also revolutionize wearable health monitoring devices that must withstand daily wear and tear.

The technology has the potential to transform society more broadly by reducing electronic waste and mitigating environmental harm caused by consumer-based electronics’ short lifespans. Most consumer electronics have a lifespan of only one or two years, contributing billions of pounds of toxic waste each year.

“If we can begin to create materials that are able to passably and autonomously detect when damage has happened, and then initiate these self-repair mechanisms, it would really be transformative,” Markvicka said.

Rewritten Article:

In a breakthrough that’s straight out of science fiction, a team of engineers at Caltech has developed a real-life Transformer that can morph in mid-air, allowing it to smoothly transition from flying to rolling on the ground. This innovative technology has far-reaching implications for commercial delivery systems and robotic explorers, making it an exciting development in the field of robotics.

The new robot, dubbed ATMO (aerially transforming morphobot), uses four thrusters to fly but can transform into a ground-rolling configuration using a single motor that lifts its thrusters up or down. This unique design allows ATMO to change its shape and function seamlessly, enabling it to adapt to various environments and situations.

According to Ioannis Mandralis, the lead author of the research paper published in Communications Engineering, “We designed and built a new robotic system inspired by nature – by the way that animals can use their bodies in different ways to achieve different types of locomotion.” For example, birds fly and then change their body morphology to slow themselves down and avoid obstacles. Mandralis adds, “Having the ability to transform in the air unlocks a lot of possibilities for improved autonomy and robustness.”

However, mid-air transformation also poses challenges due to complex aerodynamic forces that come into play both because the robot is close to the ground and because it is changing its shape as it morphs. Mory Gharib, the Hans W. Liepmann Professor of Aeronautics and Medical Engineering, notes that “Even though it seems simple when you watch a bird land and then run, in reality this is a problem that the aerospace industry has been struggling to deal with for probably more than 50 years.”

To better understand these complex aerodynamic forces, the researchers ran tests in Caltech’s drone lab using load cell experiments and smoke visualization. They fed those insights into the algorithm behind a new control system they created for ATMO, which uses advanced model predictive control to continuously predict how the system will behave in the near future and adjust its actions accordingly.

“The control algorithm is the biggest innovation in this paper,” Mandralis says. “Quadrotors use particular controllers because of how their thrusters are placed and how they fly. Here we introduce a dynamic system that hasn’t been studied before. As soon as the robot starts morphing, you get different dynamic couplings – different forces interacting with one another. And the control system has to be able to respond quickly to all of that.”

The potential applications of ATMO are vast and exciting, from commercial delivery systems to robotic explorers. With its unique ability to transform in mid-air and adapt to various environments, this technology has the potential to revolutionize the field of robotics and beyond.

The researchers at Linköping University in Sweden have achieved a significant milestone in the development of controllable flat optics. By carefully placing nanostructures on a flat surface, they have improved the performance of optical metasurfaces made from conductive plastics. This breakthrough has far-reaching implications for various fields, including video holograms, invisibility materials, sensors, and biomedical imaging.

Traditional glass lenses are often curved to refract light in different ways. However, these lenses take up space and become impractical when miniaturized. Flat lenses, on the other hand, offer a promising alternative. They are made of metalenses, which form a rapidly growing field of research with great potential. Despite their limitations, metasurfaces have garnered significant attention due to their ability to control light using nanostructures placed in patterns on a flat surface.

“Metasurfaces work by placing nanostructures in patterns on a flat surface and becoming receivers for light,” explains Magnus Jonsson, professor of applied physics at Linköping University. “Each receiver captures the light in a certain way, allowing the light to be controlled as desired.”

However, one major challenge facing metasurface technology is the inability to adjust their function after manufacture. Researchers and industry have requested features such as turning metasurfaces on and off or dynamically changing the focal point of a metalens.

In 2019, Magnus Jonsson’s research group at the Laboratory of Organic Electronics showed that conductive plastics can crack this nut. They demonstrated that the plastic could function optically as a metal and be used as a material for antennas building a metasurface. The ability to oxidize and reduce allowed the nanoantennas to be switched on and off.

The same research team has now improved performance up to tenfold by precisely controlling the distance between the antennas, which helps each other through collective lattice resonance. This advancement enables conductive polymer-based metasurfaces to provide sufficiently high performance for practical applications.

While the researchers have successfully manufactured controllable antennas from conducting polymers for infrared light, their next step is to develop the material to be functional in the visible light spectrum as well.

This breakthrough has significant implications for various fields and opens up new possibilities for innovation. As research continues to push the boundaries of metasurface technology, we can expect to see exciting developments in video holograms, invisibility materials, sensors, and biomedical imaging equipment.