Phys.org March 19, 2018 Post-translational modification of proteins is a strategy widely used in biological systems which has remained largely untapped for the synthesis of biomaterials. As a proof of concept of this technique, an international team of researchers (USA – Duke University, Germany) reports the generation of a family of three stimulus-responsive hybrid materials—fatty-acid-modified elastin-like polypeptides—using a one-pot recombinant expression and post-translational lipidation methodology. The hybrid approach allows researchers to control self-assembly more precisely, which may prove useful for a variety of biomedical applications from drug delivery to wound healing… read more. TECHNICAL ARTICLE
Category Archives: Advanced materials
The quantum states on the surface of conducting materials can strongly interact with light
Physorg March 9, 2018 Researchers in Singapore show that Dirac semimetals are unusual in that they possess a very optically active surface due to the peculiar Fermi arc states. Surface absorption depends heavily on the polarization of light, being 100 to 1,000 times stronger when light is polarized perpendicular—rather than parallel—to the crystal’s rotational axis. This strong anisotropy offers a way of optically investigating and probing the topological surfaces states of Dirac semimetals which could host unusual opto-electronic behavior that goes beyond conventional materials… read more. TECHNICAL ARTICLE
Research team creates hydrogel adhesives to seal wounds
Physorg March 9, 2018 Researchers at Harvard University have developed a hydrogel which is a hybrid of two different polymers: a seaweed extract called alginate and polyacrylamide. When these become entangled with each other, they create a molecular network that demonstrates unprecedented toughness and resilience for a hydrogel material—on par with the body’s natural cartilage. When combined with an adhesive layer containing positively charged polymer molecules, the resulting hybrid material can bind to tissues, stretch up to 20 times its initial length, and attach to wet tissue surfaces undergoing dynamic movement… read more.
A treasure trove for nanotechnology experts
Eurekalert March 6, 2018 Starting from 108,423 unique, experimentally known 3D compounds, an international team of researchers (Switzerland, Lithuania) has identified a subset of 5,619 compounds that appear layered according to robust geometric and bonding criteria. Out of those 1,825 compounds are either easily or potentially exfoliable. For a subset of 258 compounds, they explored vibrational, electronic, magnetic and topological properties, identifying 56 ferromagnetic and antiferromagnetic systems, including half-metals and half-semiconductors. The research paves the way for groundbreaking technological applications… read more. TECHNICAL ARTICLE
When rotated at a ‘magic angle,’ graphene sheets can form an insulator or a superconductor
Physorg March 5, 2018 An international team of researchers (USA – MIT, Harvard University, Japan) created a “superlattice” of two graphene sheets stacked together at a “magic angle” of 1.1 degrees creating a precise moiré configuration. They found that at the magic angle, the two sheets of graphene exhibit nonconducting behavior similar to Mott insulators. When they applied voltage by adding small amounts of electrons to the graphene superlattice, at a certain level, the electrons broke out of the initial insulating state and flowed without resistance, as if through a superconductor. The finding provides a platform for investigating unconventional superconductivity, […]
New graphene laser technique opens door for edible electronics
Eurekalert February 28, 2018 An international team of researchers (USA – Rice University, Israel) reports a method of using multiple pulsed-laser scribing to convert a wide range of substrates into laser-induced graphene (LIG). With the increased versatility of the multiple lase process, highly conductive patterns can be achieved on the surface of a diverse number of substrates in ambient atmosphere. The use of a defocus method results in multiple lases in a single pass of the laser, further simplifying the procedure. Any carbon precursor that can be converted into amorphous carbon can be converted into graphene using this multiple lase […]
Compound could transform energy storage for large grids
Phys org February 5, 2018 A team of researchers in the US (University of Rochester, State University of New York – Buffalo) developed a method to modify polyoxometalates by replacing the compound’s methanol-derived methoxide groups with ethanol-based ethoxide ligands. They expanded the potential window during which the cluster was stable, doubling the amount of electrical energy that could be stored in the battery. The ethoxide and methoxide clusters can be generated by using methanol and ethanol. Both reagents are inexpensive, readily available and safe to use. According to the researchers the process may set a new standard in the field… […]
Vanadium dioxyde: A revolutionary material for tomorrow’s electronics
EurekAlert February 5, 2018 An international team of researchers (Switzerland, Germany) working on the EU Horizon 2020 project called Phase-Change Switch found that the atomic structure of the metal-insulator vanadium dioxide (VO2) changes as the temperature rises, transitioning from a crystalline structure at room temperature to a metallic one at temperatures above 68°C. They found that adding germanium to VO2 film can lift the material’s phase change temperature to over 100°C required for modern electronic devices. The technology is particularly effective in the frequency range crucial for space communication systems (the Ka band, with programmable frequency modulation between 28.2 and […]
A major step forward in organic electronics
Eurekalert January 11, 2018 Researchers in Sweden have shown that ladder-type polymers, such as poly(benzimidazobenzophenanthroline) (BBL), can successfully work as stable and efficient n-channel material for OECTs. BBL-based OECTs show high transconductance (up to 9.7 mS) and excellent stability in ambient and aqueous media. They have demonstrated that BBL-based n-type OECTs can be successfully integrated with p-type OECTs to form electrochemical complementary inverters. The latter show high gains and large worst-case noise margin at a supply voltage below 0.6 V. Applications of the organic components include logic circuits that can be printed on textile or paper, various types of cheap […]
Flexible bonding: hard and soft at the same time
Fraunhofer Research News January 2, 2018 Researchers in Germany have developed a new material called MetAK which is comparable to commercially available resins. Its stiffness can be determined by two hardening mechanisms: irradiation with UV light, and heat. The areas that should remain flexible are not irradiated; they are instead treated with heat, which cures them. As the rigidity is very easily adjustable, it is possible to flexibly adjust the material to the frequency range of the vibrations and compensate for them. MetAk can be cast in a specified shape making it attractive for orthopedic applications. Read more.