Silicon offers a unique combination between mechanical and electrical properties making it one of the most developed materials in semiconductor industry. However, silicon is brittle and cannot be flexed, hindering its potential for high performance electronics that is flexible, stretchable or applied to irregular shapes. Researchers have now developed a pragmatic approach to achieve high performance integrated electronic systems, including thermoelectric energy harvesters, onto flexible silicon substrates.
Researchers in Canada have demonstrated that it is possible to achieve graphite-like charge/discharge behavior in a sodium ion battery anodes through a controlled dilation of the intergraphene spacing in a tailored carbon. They utilized common peat moss as the carbon precursor, tuning the synthesis process to create macroscopically open nanoscale pseudographitic structures that also offers a unique high rate capability and superb charge-discharge cycling stability.
Previous work in stretchable, flexible electronics has shown that conventional, silicon wafer based fabrication techniques can be modified to apply electronics conformally to the heterogeneous topography of the skin. Now, researchers have demonstrated the development of a device platform that enables high precision temperature mapping of the skin in ways that have, until now, been extremely difficult in research and impossible to implement for widespread use.
The quest for efficient low-cost solutions for solar energy conversion faces many obstacles, both, fundamental and technical. As a result, even 'ideal' solar cells have maximum intrinsic efficiency - known as the Shockley-Queisser (S-Q) limit - of 33% for the illumination by the non-concentrated sunlight. A number of architectures have been proposed for reducing losses in solar cells in order to overcome the S-Q single-junction limit. Now, researchers have proposed a new way to break the fundamental S-Q limit by using a mechanism of thermal up-conversion.
As researchers continue to develop the use of graphene in energy storage devices, other two-dimensional (2D) inorganic materials like 2D transition metal disulfides have attracted extensive scientific attention. Vanadium disulfide few-layered nanosheets have been recently achieved experimentally, and in new work, scientists systematically investigated the adsorption and diffusion of lithium on the recently synthesized vanadium disulfide monolayer in comparison with MoS2 monolayer and graphite.
The construction of artificial micro- and nanomotors is a high priority in the nanotechnology field owing to their great potential for diverse potential applications, ranging from targeted drug delivery, on-chip diagnostics and biosensing, or pumping of fluids at the microscale to environmental remediation. In new work, researchers have now reported the first example of micromotors for the active degradation of organic pollutants in solution. The novelty of this work lies in the synergy between internal and external functionality of the micromotors.
Functionalized graphene holds exceptional promise for biological and chemical sensors. In new work, researchers have shown that the distinctive 2D structure of graphene oxide, combined with its superpermeability to water molecules, leads to sensing devices with an unprecedented speed. The team reports the experimental observation of the unparalleled response speed of humidity sensors based on graphene oxide, which are - to the best of the scientists' knowledge - the fastest humidity sensors ever reported.
Over the past decade, electromagnetic metamaterials have become an extremely active field of research in both the physics and the engineering communities. Metamaterials gain their properties from their structure rather than directly from their composition and show the peculiarity of having an index of refraction at optical frequencies from negative to very high positive values. Researchers have now suggested a new type of optical sensing device based on artificial metamaterials with topological darkness.