Phys.org April 12, 2023 Controllable microbial electrocatalytic activity in a miniaturized microbial fuel cells (MFCs) with unlimited biodegradable energy resources would enable simple power generation in various environmental settings. However, the short shelf-life of living biocatalysts, few ways to activate the stored biocatalysts, and extremely low electrocatalytic capabilities render the miniature MFCs unsuitable for practical use. Researchers at State University of New York at Binghamton used heat-activated Bacillus subtilis spores as a dormant biocatalyst that could survive storage and rapidly germinate when exposed to special nutrients that are preloaded in the device. A microporous, graphene hydrogel allowed the adsorption of […]
Tag Archives: Biomimetics
Resilient bug-sized robots keep flying even after wing damage
Science Daily March 15, 2023 Although robots driven by rigid actuators have demonstrated agile locomotion and manipulation, most of them lack animal-like robustness against unexpected damage. Dielectric elastomer actuators (DEAs), a class of muscle-like soft transducers, have enabled nimble aerial, terrestrial, and aquatic robotic locomotion. However, unlike muscles, DEAs suffer local dielectric breakdowns that often cause global device failure. Researchers at MIT developed DEAs that can endure more than 100 punctures while maintaining high bandwidth and power density sufficient for supporting energetically expensive locomotion such as flight. They fabricated electroluminescent DEAs for visualizing electrode connectivity under actuator damage. When the […]
Designing advanced ‘BTS’ materials for temperature and long-wave infrared sensing
Phys.org February 20, 2023 Replicating the molecular structure and functional motifs of biological compounds often provide clues to advance material designs and offers a blueprint for unprecedented functionalities. An international team of researchers (USA – Caltech, South Korea) has developed a flexible biomimetic thermal sensing (BTS) polymer that was designed to emulate the ion transport dynamics of a plant cell wall component, pectin. Using a simple yet versatile synthetic procedure, they engineered the physicochemical properties of the polymer by inserting elastic fragments in a block copolymer architecture, making it flexible and stretchable. The thermal response of the flexible polymer outperformed […]
A liquid laser that is robust in air and tunable by wind
Phys.org February 10, 2023 Lasers made solely from liquids are promising toward flexible lasers, but they are intrinsically unstable and have been inapplicable to steady operation under ambient conditions unless they are enclosed in a tailored container or a matrix to prevent the evaporation of the liquid. To simulate the near-perfect water droplets that form on the lotus leaves and roll off, an international team of researchers (Japan, Germany) mixed 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) with a dye that allowed it to become a laser. The droplets were highly robust and worked as efficient long-lasting laser oscillators. The lasing wavelength was sensitively […]
Recreating the natural light-harvesting nanorings in photosynthetic bacteria
Science Daily January 31, 2023 Photosynthesis in plants and some bacteria relies on light-harvesting (LH) supramolecules which come in different structures. So far, these LH molecules have not been artificially prepared. Researchers in Japan demonstrated that mixing a chlorophyll derivative with naphthalenediamide in an organic solvent leads to the formation of dimers that spontaneously self-assembled into ring-shaped structures, each several hundred nanometers in diameter. They observed that chlorophyll dimers, molecules composed of two chlorophyll units linked by naphthalene, initially self-assembled into stable wavy nanofibers. Upon heating these nanofibers at 50°C, they disassembled into smaller nanoring precursors whose ends eventually joined […]
Breathing supercapacitor
Nanowerk January 13, 2023 Currently commercialized supercapacitors still suffer from limited energy densities. Taking inspiration from anolis lizard, an international team of researchers (UK, China) has developed a supercapacitor with a “breathing” electrode. To breathe underwater the lizard brings along an air bubble that is attached to a layer of scales on their head. Under water, it repeatedly breathes this bubble in and out. The researchers used chlorine gas which iteratively reinspires in porous carbon materials, that improves the energy density by orders of magnitude. They showed that porous carbon with pore size around 3 nm delivers the best chlorine […]
Preventing vehicle crashes by learning from insects
Science Daily January 17, 2023 For detecting a potential collision at night to alert the driver or, maneuvering system of an autonomous vehicle, current technologies utilize resource draining and expensive solutions such as LiDAR or image sensors coupled with extensive software running sophisticated algorithms. In contrast, insects perform the same task of collision detection with frugal neural resources. Researchers at Pennsylvania State University have shown that insect-inspired collision detection algorithms, when implemented in conjunction with in-sensor processing and enabled by innovative optoelectronic integrated circuits based on atomically thin and photosensitive memtransistor technology, can greatly simplify collision detection at night. The […]
A step towards solar fuels out of thin air
Science Daily January 4, 2023 Taking inspiration from the way plants can convert sunlight into chemical energy using carbon dioxide from the air, researchers in Switzerland have invented a solar-powered artificial leaf, built on a novel electrode capable of harvesting water from the air for conversion into hydrogen fuel. The system combines semiconductor-based technology and the electrodes that are porous and transparent. When the device was simply exposed to sunlight, it took water from the air and produced hydrogen gas. The coating of various semiconductors on the substrates was established including Fe2O3 (chemical bath deposition), CuSCN and Cu2O (electrodeposition), and […]
Proposing a new idea for spacecraft propulsion that involves dynamic soaring
Phys.org December 6, 2022 Inspired by the dynamic soaring maneuvers performed by sea birds and gliders in which differences in wind speed are exploited to gain velocity, an international team of researchers (Canada, USA – industry) proposed a technique in which a lift-generating spacecraft circles between regions of the heliosphere that have different wind speeds, gaining energy in the process without the use of propellant and only modest onboard power requirements. Detailed models of the spacecraft trajectory were developed to predict the potential velocity gains and the maximum velocity that might be achieved in terms of the lift-to-drag ratio of […]
Microscopic chains that mimic DNA
Phys.org November 29, 2022 DNA conformation is well understood for biological processes. An international team of researchers (Austria, Poland, Italy) focused on chains interlocking the rings and observed their behavior and how they could be used to design innovative materials. They showed that circular polycatenanes have physical and geometrical properties very similar to those of double stranded DNA rings. They demonstrated that the connection of local and global properties holds for these structures too, that is there is a connection between what occurs in a part of the structure and in its whole. The amount of twist of the polycatenanes […]