Nanowerk May 27, 2020 To use body heat to charge some types of micro-devices and sensors requires lightweight, non-toxic, wearable, and flexible thermoelectric generators. Researchers in Japan studied the thermoelectric properties of a highly conductive thiophene-based polymer, called PBTTT. They found that doping the polymer with a thin ion electrolyte gel improves conductivity and infiltrates the polymer successfully when a specific electric voltage is applied. Doping it with a critical amount of electrolyte untwists the highly twisted chain and creates links between its crystalline parts, improving electron conductivity. They are now looking into ways to optimize the thermoelectric performance of […]
Category Archives: Advanced materials
Making quantum ‘waves’ in ultrathin materials
EurekAlert May 14, 2020 To understand how plasmons operate in quasi 2D crystals an international team of researchers (USA – UC Berkeley, Lawrence Berkeley National Laboratory, research organization, Germany) characterized the properties of both nonconductive and conductive electrons in a monolayer of the TMD tantalum disulfide. Using the new algorithms they developed to compute the material’s electronic properties, they found the plasmons in quasi 2D TMDs are much more stable – for as long as approximately 2 picoseconds than previously thought. Their findings also suggest that plasmons generated by quasi 2D TMDs could enhance the intensity of light by more […]
Breathable second skin materials provide smart protection against chemical and biological agents
Nanowerk May 6, 2020A team of researchers in the US (Lawrence Livermore National Laboratory, U.S. Army Natick Soldier Research, Development and Engineering Center, MA) demonstrated a smart material that is both breathable and protective by successfully combining a base membrane layer comprising trillions of aligned carbon nanotube pores and a threat-responsive polymer layer grafted onto the membrane surface. The carbon nanotubes could easily transport water molecules through their interiors while also blocking all biological threats, which cannot fit through the tiny pores. To add protection against chemical hazards, a layer of polymer chains is grown on the material surface, which […]
Researchers pave the way to designing omnidirectional invisible materials
EurekAlert May 7, 2020 Researchers in Spain have demonstrated that Maxwell’s equations, as well as the acoustic and elastic wave equations, also possess an underlying supersymmetry in the time domain. They explored the consequences of this property in the field of optics, obtaining a simple analytic relation between the scattering coefficients of numerous time-varying systems, and uncovering a wide class of reflectionless, three dimensional, all-dielectric, isotropic, omnidirectional, polarisation-independent, non-complex media. These unprecedented features may enable the creation of novel reconfigurable devices, including invisible materials, frequency shifters, isolators, and pulse-shape transformers…read more. Open Access TECHNICAL ARTICLE
Shape-shifting carbon fibre could replace mechanical systems for planes and more
Nanowerk May 7, 2020 Researchers in Sweden have developed a material that is manufactured from commercial carbon fibers and a structural battery electrolyte and uses lithium-ion insertion to produce shape changes at low voltages. It is an electrically controlled solid-state morphing composite material that is lightweight and has a stiffness higher than aluminum. It is capable of producing large deformations and holding them with no additional power, albeit at low rates. A proof-of-concept material in a cantilever setup was used to show morphing. Analytical modeling showed good correlation with experimental observations. The concept presented shows considerable promise and paves the […]
Electrical manipulation of magnetic particle allows for large high-speed memory
Phys.org April 20, 2020 Antiferromagnetic materials seem harder to work with but have many useful properties and they are less subject to external magnetic fields due to a unique arrangement of their constituent parts making it harder to manipulate the material as needed. According to researchers in Japan in antiferromagnetic manganese-tin alloy Mn3Sn Weyl fermions exist at Weyl points in momentum space. They have two possible states that could represent binary digits. They found that it is possible to switch a Weyl point between these states with an external electrical current applied to neighboring thin layers of Mn3Sn and either […]
Carbon nanostructure created that is stronger than diamonds
Science Daily April 13, 2020 An international team of researchers (USA – UC Irvine, UC Santa Barbara, industry, Germany) has succeeded in conceptualizing and fabricating the material which consists of closely connected closed-cell plates instead of the cylindrical trusses common in such structures over the past few decades. They have shown that the design improves the average performance of cylindrical beam-based architectures by up to 639 percent in strength and 522 percent in rigidity. One of the group’s innovations was to include tiny holes in the plates that could be used to remove excess resin from the finished material…read more. […]
Now metal surfaces can be instant bacteria killers, thanks to new laser treatment technique
Technology.org April 9, 2020 Researchers at Perdue University have developed a one-step laser-texturing technique that effectively enhances the bacteria-killing properties of copper’s surface. The nanoscale patterns produce a rugged texture that increases surface area, allowing more opportunity for bacteria to hit the surface and rupture on the spot. The technique also makes the surface hydrophilic. In tests against pathogenic bacterial strains with different concentrations including Pseudomonas aeruginosa, and methicillin‐resistant Staphylococcus aureus (MRSA USA300) at 105 CFU mL−1, and Escherichia coli and Staphylococcus aureus at high bacterial concentrations of 108 CFU mL−1 the laser treated copper needed 40, 90, 60, and […]
Novel MOF is potential next-gen semiconductor
Phys.org March 23, 2020 Researchers at Clemson University constructed a novel double-helical MOF (dhMOF) by introducing a new butterfly-shaped electron-rich π-extended tetrathiafulvalene ligand equipped with four benzoate groups (ExTTFTB). To create a charge transport pathway capable of conducting electricity, they diffused iodine vapor into the porous MOF, causing one strand to become electron deficient while the other remained electron rich. Electrical conductivity surged from 10–8 S/m up to 10–4 S/m range after iodine treatment. Thus, the introduction of the electron-rich ExTTFTB ligand afforded a novel double-helical MOF architecture featuring ovoid cavities and unique charge-delocalization pathways and delivered a new tool […]
Two-dimensional metals open pathways to new science
Nanowerk March 9, 2020 To make 2D metals key ingredients in next-generation quantum and optoelectronic devices they must be stabilized against environmental degradation and integrated into heterostructure devices at the wafer scale. A team of researchers in the US (Pennsylvania State University, Lawrence Berkeley National Laboratory, Oak Ridge National Laboratory) has demonstrated large-area, environmentally stable, single-crystal 2D gallium, indium and tin that are stabilized at the interface of epitaxial graphene and silicon carbide. The 2D metals are covalently bonded to SiC below but present a non-bonded interface to the graphene overlayer; that is, they are ‘half van der Waals’ metals […]