Science Daily September 7, 2021 Using colloidal gels of fullerite C60 and C70 nanocrystals researchers at the University of Central Florida have developed superhydrophobic films and coatings. They demonstrated that despite the high surface energy of these van der Waals molecular crystals their gelation can create films having self-affine fractal surfaces with multiscale roughness. In experiments when submerged in water the material stayed dry up to 3 h even at a water depth of two feet and exhibit the plastron effect. According to the researchers non-wettable films of such materials are unique as fullerites get photosensitized instantaneously generating extremely high […]
Tag Archives: Biomimetics
Lightweight composite material inspects itself: Changes in color indicate deformations
Science Daily August 23, 2021 An international team of researchers (Switzerland, UK) developed a new type of laminate that changes color as soon as the material is deformed. The laminate is composed of alternating layers of a plastic polymer and artificial nacre or mother-of-pearl and is modelled on the biological example of the mussel shell. It consists of glass platelets arranged in parallel, which are compacted, sintered, and solidified using a polymeric resin making it extremely hard and break-resistant. The second layer consists of a polymer and an indicator molecule synthesised specifically for this application. The molecule is activated as […]
Microbially produced fibers: Stronger than steel, tougher than Kevlar
Phys.org July 21, 2021 A problem associated with recombinant spider silk fiber is the need to create β-nanocrystals, a main component of natural spider silk, which contributes to its strength. Researchers at Washington University redesigned the silk sequence by introducing amyloid sequences that have high tendency to form β-nanocrystals. They created different polymeric amyloid proteins using three well-studied amyloid sequences as representatives. The resulting proteins had less repetitive amino acid sequences than spider silk, making them easier to be produced by engineered bacteria. The longer the protein, the stronger and tougher the resulting fiber. The 128-repeat proteins resulted in a […]
Electrohydraulic arachno-bot a fascinating lightweight
EurekAlert June 16, 2021 Researchers at the University of Colorado exploited the principles of spiders’ joints to drive articulated robots without any bulky components and connectors. The Electrohydraulic Soft-actuated joints (SES) joints comprised of both rigid and softer elements can be used in many different configurations. The joints use electrostatic forces to locally pressurize a hydraulic fluid, and cause flexion of a segmented structure. SES joints with rotation angles up to 70° blocked torques up to 70 mN m, and specific torques up to 21 N m kg−1 have been demonstrated. SES joints demonstrated high speed operation, with measured roll-off […]
Scientists develop the ‘evotype’ to unlock power of evolution for better engineering biology
Phys.org June 8, 2021 Researchers in the UK have developed the concept of the evotype to help biological engineers both harness, design, and capture the evolutionary potential of a biosystem. The evotype can be broken into three key parts: Variation, Function, and Selection, with each of these offering a tuning knob for bioengineers to control the possible paths available to evolution. Many of the tools already available to bioengineers fitted nicely into their framework when considered from an evolutionary perspective. Their concept of the evotype not only provides a means for developing biotechnologies that can harness evolution in new ways, […]
Researcher uses bat-inspired design to develop new approach to sound location
Science Daily April 15, 2021 Inspired by the bat ears, researchers at Virginia Tech designed a soft-robotic sensor that mimics fast non-rigid deformation of the ears in bats. They placed the ear above a microphone, creating a mechanism similar to that of a bat. The fast motions of the fluttering outer ear of the bat created Doppler shift signatures. To interpret this complex pattern, they trained a computer to provide the source direction associated with each received echo using deep neural network. Once the direction of the sound was determined, the control computer would rotate the rig so that the […]
Wafer-thin nanopaper changes from firm to soft at the touch of a button
Science Daily March 24, 2021 Mimicking the sea cucumbers which adapt and strengthen their tissue so that their soft exterior immediately stiffens when attacked by predators, researchers in Germany have developed a mechanism to strengthen and stiffen a material using electric current. They developed cellulose nanofibrils/polymer nanopapers with tailor-made interactions by deposition of thin single-walled carbon nanotube electrode layers for Joule heating. Application of DC at specific voltages translates into significant electrothermal softening via dynamization and breakage of the thermo-reversible supramolecular bonds. The altered mechanical properties are reversibly switchable in power on/power off cycles. Currently a power source is needed […]
An intelligent soft material that curls under pressure or expands when stretched
Nanowerk February 24, 2021 Existing perceptive soft actuators require complex integration and coupling between the discrete functional units to achieve autonomy and intelligently interact with humans and the environment. Researchers in China have developed actuators with embodied sensing, actuation, and control at the single-unit level by synergistically harnessing the mechanosensing and electrothermal properties of liquid metal (LM) to actuate the thermally responsive liquid crystal elastomer (LCE). They created multifunctional LM circuits on the LCE surface using a simple and facile methodology based on magnetic printing. The fluidic LM circuit can be utilized as a conformable resistive heater, and a sensory […]
Active camouflage artificial skin in visible-to-infrared range
Phys.org December 2, 2020 Researchers in South Korea have developed a multispectral imperceptible skin that enables human skin to actively blend into the background both in the IR‐visible integrated spectrum only by simple temperature control with active cooling and heating. The thermochromic layer on the outer surface of the device, which produces various colors based on device surface temperature, expands the cloaking range to the visible spectrum and ultimately completes day‐and‐night stealth platform simply by controlling device temperature. In addition, the scalable pixelization of the device allows localized control of each autonomous pixel, enabling the artificial skin surface to adapt […]
Bioinspired metagel with broadband tunable impedance matching
Phys.org November 10, 2020 The concept of impedance matching has been established in electrical, acoustic, and optical engineering to maximize energy transmission from a source through a media. However, existing design of acoustic impedance matching, which extends exactly by a quarter wavelength, sets a fundamental limit of narrowband transmission. An international team of researchers (China, USA – MIT, Harvard University, Duke University, South Korea, Denmark, Canada, Scotland, Germany) has shown that a class of bioinspired metagel impedance transformers can overcome this limit. The transformer embeds a two-dimensional metamaterial matrix of steel cylinders into hydrogel. Using experimental data of the biosonar […]