Phys.org September 3, 2021 To improve the movement and response time for electrochemical actuator devices that operate in liquid a team of researchers at the University of Houston has developed electrochemical actuator that uses specialized organic semiconductor nanotubes (OSNTs). The device demonstrated excellent performance, low power consumption/strain, a large deformation, fast response, and excellent actuation stability. The enormous effective surface area of the nanotubular structure which facilitates the ion transport and accumulation results in high electroactivity and durability. The work provides new opportunities for next-generation actuators that can be utilized in artificial muscles and biomedical devices…read more. TECHNICAL ARTICLE
Tag Archives: Advanced materials
Stretching the capacity of flexible energy storage (w/video)
Nanowerk September 8, 2021 In spite of the excellent electrical and electrochemical properties, two-dimensional transition metal carbide (MXene) is often limited by the high stiffness for the direct implementation in next-generation stretchable and wearable energy storage devices. After screening for the thickness, researchers in China identified the crumpled MXene film of ∼3 μm in thickness as the optimal choice to mitigate the crack formations under large and repetitive mechanical strains. The as-prepared symmetric supercapacitor demonstrated a high specific capacitance of ∼470 mF cm–2, ultrahigh stretchability up to 800% area strain, and >90% retention of the initial capacitance after 1000 stretch–relaxation […]
Light-induced shape shifting of MXenes
Phys.org September 1, 2021 MXenes are two-dimensional sheets of transition metal carbides or nitrides in the form of few-atom-thick single layers. An international team of researchers (Germany, Switzerland) has found a new way to enhance the properties of MXenes by shining fast light pulses on them. Using ultrafast electron microscopy with atomic spatial resolution they showed that the laser energy transfers to the atomic lattice in a record-breaking time of merely 230 femtoseconds. They also found that femtosecond laser light can be used to switch back and forth between the originally flat surface structure of the MXene and a nano-wave […]
New family of ferroelectric materials raises possibilities for improved information and energy storage
Phys.org August 31, 2021 Researchers at Pennsylvania State University used magnesium-substituted zinc oxide thin films to make tiny capacitors. They could set their polarization orientation so that their surface charge is either plus or minus. The setting is nonvolatile. This type of storage requires no additional energy. The magnesium-substituted zinc oxide thin films can be deposited at much lower temperatures than other ferroelectric materials. Substrate temperature can be lowered to ambient conditions, and when doing so, capacitor stacks show only minor sacrifices to crystal orientation and nearly identical remanent polarization values; however, coercive fields drop below 2 MV/cm. This ability could […]
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 […]
New Exotic Magnetic Quasiparticle: “Skyrmion Bundle” Joins Topological Zoo
SciTech Daily August 23, 2021 Although theory has proposed “skyrmion bags” and “high-order skyrmions” as multi-Q topological magnetic structures, their experimental observations remain elusive. Using 3D micromagnetic simulation approach, an international team of researchers (China, USA – University of New Hampshire) proposed a new 3D multi-Q topological structure, skyrmion bundle. Through experimental verification they found collective motions and topological sign dependence of Hall sideway shifts of skyrmion bundles driven by nanosecond pulsed currents. Skyrmion bundles can serve as information carriers applied in distinct spintronic devices such as multi-state memory and information interconnect and should pave a new field of topological […]
Metasurfaces control polarized light at will
Phys.org August 14, 2021 A team of researchers in the US (Harvard University, industry) has proposed a new class of computer-generated holograms, called Jones matrix holograms, whose far-fields have designer-specified polarization response. They have provided a simple procedure for their implementation using form-birefringent metasurfaces. Jones matrix holography generalizes past work with a consistent mathematical framework, particularly in the field of metasurfaces. They have demonstrated holograms whose far-fields implement parallel polarization analysis and custom waveplate-like behavior. The new approach could lead to applications in diverse fields including imaging, microscopes, displays, and astronomy. The work shows that the ability to switch between […]
Scientists Discover How to Make Glass So Hard, It Can Even Scratch Diamond
Science Alert August 13, 2021 An international team of researchers (China, Sweden, USA – Harvard university, Germany, Russia) has discovered the critical proportion of crystallized and amorphous carbon needed to create a glass with remarkable properties that won’t weaken under intense pressure. By subjecting spheres of carbon atoms to intense pressure and baking at temperatures between 1,000 and 1,200 degrees Celsius they obtained glassy materials dubbed AM – I, II and III. After tests they mapped the way the atoms bonded with one another, showing they all operated as a semiconductor on a level comparable with amorphous silicon. After Vickers […]
3D Kirigami Building Blocks Designed To Make Dynamic Metamaterial Structures
ScitechDaily.com August 11, 2021 In a proof-of-concept study a team of researchers in the US (North Carolina State University, Yale University) cut bulk materials into spatially closed-loop to construct a new class of 3D kirigami metamaterials. The module is transformable with multiple degrees of freedom that can transform into versatile distinct daughter building blocks. Depending on how the cubes are connected to each other, the building blocks can be folded into more than 300,000 different designs. Their conformable assembly creates a wealth of reconfigurable and disassemblable metamaterials with diverse structures and unique properties, including reconfigurable 1D column-like materials, 2D lattice-like […]
Metamaterials research challenges fundamental limits in photonics
Phys.org August 10, 2021 Previous research was limited to modifying either absorption or refraction in metamaterials. Researchers at Cornell University have demonstrated that if both properties are modulated in time, it is possible to absorb electromagnetic waves much more efficiently than in a static structure, or in a structure in which either one of these two degrees of freedom is modulated individually. They combined these two aspects together to create a much more effective system. The findings may lead to the development of new metamaterials with wave absorption and scattering properties that far outperform what is currently available. The research […]