Phys.org March 19, 2020 A team of researchers in the US (Duke University, Michigan State University, MIT) has demonstrated a robust and high-performance stretchable electrode based on biaxially crumpled Au-coated carbon nanotube forest. It has nearly identical electrochemical performance at different measured charge/discharge rates under different strain conditions and a maximum specific capacitance of ∼6 mF cm−2 at the current density of 40 mA cm−2 under large strains, exhibiting superior mechanical and electrochemical stability. The researchers envision the supercapacitor being part of a power-independent, stretchable, flexible electronic system for applications such as wearable electronics or biomedical devices…read more. Open Access […]
Tag Archives: Materials science
Lights, camera, action… the super-fast world of droplet dynamics
Eurekalert February 25, 2020 The chemistry behind emerging 3D-printing technologies involves having chemicals deposited onto a surface in a highly specific way. But how to make that happen in the printing process is poorly understood. Researchers in the UK used two synchronised cameras to see what was happening both on the surface and inside the droplets and to make a better assessment of mixing, whether they have mixed or has one droplet just passed over the other. The research provides understanding of the way chemicals react when they are deposited by a 3D printer which will lead to significant advances […]
Observation of non-trivial superconductivity on surface of type II Weyl semimetal
Phys.org February 25, 2020 An international team of researchers (China, USA – University of Tennessee, Israel) reported the experimental evidence for the unconventional superconductivity generated by the surface states in TaIrTe4 from both scanning tunneling microscopy/ spectroscopy (STM/STS) and electrical transport measurements. They demonstrated its superconductivity by both the superconducting gap from STS and the consistent resistance drop from electrical transport. The thickness-independence of ultralow critical current and angular dependence of upper critical field (Bc2) indicate that the superconductivity occurs only in the surface states. The research offers a novel platform for exploring topological superconductors and may contribute to the […]
Shining a new light on biomimetic materials
Phys.org February 25, 2020 Self-trapped light beams hold potential for optical interconnects, applications in image transmission, rerouting light, logic gates for computing and for the next-generation light-guiding-light signal processing. However, self-trapping suffers from either the need for large incident beam power and loss of beam interactions at large distances, or it is slow and irreversible. An international team of researchers (Canada, USA – Harvard University, University of Pittsburgh) has shown that rapidly and repeatably switchable self-trapped laser beams with remote communication capabilities can be elicited at exceptionally small intensities in a pliant, processable hydrogel functionalized with a chromophore. According to […]
Using light to put a twist on electrons
Science Daily February 26, 2020 Chirality occurs not in the structure of the molecules themselves, but in a kind of patterning in the density of electrons within the material. An international team of researchers (USA – MIT, Carnegie Mellon, Northeastern University, Cornell University, Drexel University, Taiwan, Singapore, Japan) found that while titanium diselenide at room temperature has no chirality to it, as its temperature decreases it reaches a critical point where the balance of right-handed and left-handed electronic configurations gets thrown off and one type begins to dominate. They found that this effect could be controlled and enhanced by shining […]
If you want to catch more light, twist it
Nanowerk January 31, 2020 The bulk photovoltaic effect is a way to convert light into electrical current. An international team of researchers (USA – Boston College, UCLA, Germany, Switzerland) developed microscopic devices based on the Weyl semimetal tantalum arsenide. They had larger bulk photovoltaic effect than seen before. The devices they developed absorbed mid-infrared light, an important wavelength for devices that conduct chemical and thermal imaging as well as waste heat recovery. The observed magnitude and wavelength range of the shift current advances our fundamental understanding of the effects of topology in materials. It also demonstrates the utility of Weyl […]
New quantum switch turns metals into insulators
EurekAlert February 3, 2020 In a Mott insulator free flow of electrons is facilitated by reducing the strength of the repulsive interaction between electrons, or by changing the number of electrons. An international team of researchers (Canada, Germany, Switzerland, USA – Lawrence Berkeley National Laboratory, Ohio State University, Oak Ridge National Laboratory, South Korea) explored a way to alter the very quantum nature of the material to enable a metal-insulator transition to occur. They found that in Sr2IrO4 coupling the spin to the orbital angular momentum slows the electrons down to such an extent that they become sensitive to one […]
A megalibrary of nanoparticles
Nanowerk January 23, 2020 There is a lot of interest in the world of nanoscience in making nanoparticles that combine several different materials. But the current process is complex, long and time consuming. Researchers at the Pennsylvania State University have developed two design guidelines, based on interfacial reactivity and crystal structure relations that enable the rational synthesis of a heterostructured nanorod megalibrary. They defined synthetically feasible pathways to 65,520 distinct multicomponent metal sulfide nanorods having as many as 6 materials, 8 segments, and 11 internal interfaces by applying up to seven sequential cation-exchange reactions to copper sulfide nanorod precursors. They […]
Engineers develop ‘chameleon metals’ that change surfaces in response to heat
Phys.org January 13, 2020 Researchers at Iowa State University started with a liquid metal alloy of gallium, indium and tin synthesized into particles covered with a smooth oxide shell that has been chemically stabilized. As the particles are heated, the surface thickens and stiffens and begins to behave more like a solid. Eventually the surface breaks, allowing the liquid metal inside to come to the surface. The most reactive, gallium, breaks through first. More heat brings indium to the surface. And the highest heat—about 1,600 degrees Fahrenheit—brings out florets of tin. Time, temperature and oxygen levels are carefully controlled by […]
Tweaks behind the rebirth of nearly discarded organic solar technologies
Science Daily December 19, 2019 Unlike silicon solar technology, non-fullerene acceptors (NFAs) can be shaped, made semi-transparent or colored and fine-tuned to free up and move electrons to generate electricity. Researchers at Georgia Institute of Technology have modeled tiny tweaks to molecular shapes and calculated corresponding energy conversion in a common NFA electron donor/acceptor pairing. Improved performance came from tweaks to a tiny component, a methoxy group, on the acceptor, and two positions out of four possible positions it took boosted the conversion of light into electricity from 6% to 12%…read more. Open Access TECHNICAL ARTICLE