MIT News November 11, 2020 A camel’s coat, or a person’s clothing, can help to reduce loss of moisture while at the same time allowing enough sweat evaporation to provide a cooling effect. Tests have showed that a shaved camel loses 50 percent more moisture than an unshaved one, under identical conditions. Researchers at MIT have developed a system with a two-layer material with the bottom layer, substituting for sweat glands. It consists of hydrogel, a gelatin-like substance that consists mostly of water, contained in a sponge-like matrix from which the water can easily evaporate. This is covered with an […]
Tag Archives: Biomimetics
A flexible color-changing film inspired by chameleon skin (w/video)
Nanowerk October 21, 2020 By tensing or relaxing their skin, chameleons can change the way light reflects from guanine crystals under the surface, producing structural coloration. The structural colors are different from the pigments that give many other creatures their hues. Currently available materials for mimicking chameleon skin is difficult to produce. Researchers in China introduced a flexible network structure in cellulose nanocrystals (CNCs), exerting a bridge effect for the rigid nanomaterials. These films display high flexibility with a fracture strain of up to 39%. Notably, stretching-induced structural color changes visible to the naked eye are realized, for the first […]
Materials scientists discover design secrets of nearly indestructible insect
Nanowerk October 21, 2020 The ironclad beetle is one formidable insect which has an exoskeleton that is one of the toughest, most crush-resistant structures known to exist in the biological world. An international team of researchers (USA – UC Riverside, Purdue University, UT San Antonio, Lawrence Berkeley National Laboratory, UC Irvine, Japan) used advanced microscopy, spectroscopy and in situ mechanical testing, and identified multiscale architectural designs within the exoskeleton of the beetle, and examined the resulting mechanical response and toughening mechanisms. They highlighted a series of interdigitated sutures, the ellipsoidal geometry and laminated microstructure which provide mechanical interlocking and toughening […]
Researchers use flying insects to drop sensors from air, land them safely on the ground
TechXplore October 8, 2020 In addition to the challenges of achieving low-power consumption and long-range communication, airdropping wireless sensors is difficult because it requires the sensor to survive the impact when dropped in mid-air. Researchers at the University of Washington designed insect-scale wireless sensors that come fully integrated with an onboard power supply and a lightweight mechanical actuator to detach from the aerial platform. The 37 mg mechanical release mechanism can drop the sensor during flight, using only 450 μJ of energy as well as a wireless communication link that can transmit sensor data at 33 kbps up to 1 […]
Achieving invisibility: Cross-wavelength invisibility integrated with invisibility tactics
Phys.org September 30, 2020 Oceanic animals and their predators employ a cross-wavelength detection strategy. Inspired by these animals an international team of researchers (China, USA – UC Berkeley, Lawrence Berkeley National Laboratory, Duke University) proposed a new concept of cross-wavelength invisibility that integrated a variety of invisibility tactics. They presented a Boolean metamaterial design strategy to balance divergent material requirements across cross-scale wavelengths. As a proof of concept, they simultaneously demonstrated longwave cloaking and shortwave transparency using a nanoimprinting technique. The work extended stealth techniques from individual strategies of invisibility targeting a single-wavelength spectrum to integrated invisibility targeting cross-wavelength applications. […]
Researchers create fly-catching robots
TechXplore September 28, 2020 An international team of researchers (Austria, Germany) has created a soft robot and demonstrated a series of simulation-guided lightweight, durable, untethered, small-scale soft-bodied robots that perform large-degree deformations at high frequencies up to 100 Hz. They are driven at very low magnetic fields down to 0.5 mT and exhibit a specific energy density of 10.8 kJ m−3 mT−1. They observed asynchronous strongly nonlinear cross-clapping behavior of the robots in experiments and analyzed by simulation, breaking ground for future designs of soft-bodied robots. The robots walk, swim, levitate, transport cargo, squeeze into a vessel smaller than their dimensions and can […]
Anti-reflective nanocoating inspired by fly eyes
Nanowerk September 16, 2020 Insect eyes have an anti-reflective coating which has been shown to provide anti-adhesive functionality. Researchers in Switzerland demonstrated a clear link between the morphology and function of the nanocoatings on Drosophila corneas. They found that nanocoatings that consist of individual protrusions have better anti-reflective properties, whereas partially merged structures have better anti-adhesion properties. Using biochemical analysis and genetic modification techniques they reverse engineered the protein Retinin and corneal waxes as the building blocks of the nanostructures and established low-cost production of Retinin. Mixing this synthetic protein with waxes they forward engineered various artificial nanocoatings with insect-like […]
Swarming locusts inspire new collision detector
Physics World September 7, 2020 Collision avoidance models based on image processing algorithms have been implemented using analogue very-large-scale-integration designs, but none is as efficient as this neuron in terms of energy consumption or size. The lobula giant movement detector (LGMD) neuron in locusts can detect an approaching object and prevent collisions within a swarm of millions of locusts. This single neuronal cell performs nonlinear mathematical operations on visual stimuli to elicit an escape response with minimal energy expenditure. An international team of researchers (USA – Pennsylvania State University, India) developed a nanoscale collision detector that mimics the escape response […]
Moth-eye nanostructures make good anti-icing coatings
Physics World September 3, 2020 Researchers in Vietnam fabricated moth eye structure on the quartz substrate covered with a flat paraffin layer to isolate it in a cold and humid environment. The paraffin layer only stayed on the top of the nanostructure, separated it from the outside environment to obstruct heat energy being transferred to the cold substrate, and prevented the wetting transition, which was observed regularly on the rough surface. Numerous air blocks trapped inside the nanostructure also contributed to delayed heat transfer, leading to an increase in the freezing time of the attached water droplet. The nanostructure coated […]
Self-healing soft material outsmarts nature
Nanowerk July 27, 2020 Current self-healing materials have shortcomings such as low healing strength and long healing times limit their practical application. An international team of researchers (USA – State University of Pennsylvania, Germany, Turkey) studied the molecular structure and amino acid sequences of squid proteins and developed a new stretchable biosynthetic material using protein engineering. The squid takes longer to heal because the molecular structure of the proteins inside its tentacles is not perfectly intertwined. With the laboratory-developed squid-inspired material, the scientists changed the nanostructure of the molecules until they created crosslinks between all of them in such a […]