Lithium-sulfur (Li-S) batteries, which employ sulfur as cathode and metallic lithium as anode materials, have been extensively studied as promising alternatives to the widely used lithium-ion batteries because - theoretically - they can render 3-6 times higher energy density. In practice, though, it has proven challenging to approach that theoretical value. Specifically, the rapid capacity fading, low Coulombic efficiency, and irreversible loss of active materials have impeded large-scale commercial use of Li-S batteries. Researchers now have shown that trapping lithium polysulfide species on (nanoscale) host materials is an effective way to overcome these challenges.
Nanomaterials like graphene and fullerenes provide an excellent platform to enhance weak signals from biomarkers. While graphene and fullerenes perform very well for detecting isolated biomarkers, their ability to amplify emission of biomarkers in a real physiological milieu is limited due to their strong interactions with other biomolecules such as proteins and lipids. A team of researchers now have developed new sensing platforms that use two-dimensional materials beyond graphene.
In order to make robots and robotic technology more human-like and more human-friendly, smart skin technology is a critical element that helps robots sense the world. These electronic or smart skins could help machines to accurately perceive the environment and better assist human owners. By applying the triboelectric effect and planar electrostatic induction, researchers for the first time have created a self-powered analogue smart skin.
Modern liquid crystals devices utilize high resistivity liquid crystals characterized by negligibly small concentration of mobile ions. However, these devices are prone to uncontrolled ionic contamination. This contamination can easily happen at any stage of the device fabrication or while operating the device. Ions in liquid crystals can compromise the overall performance of the device by leading to many negative side effects such as image sticking, image flickering, and slow response. Solving these problems requires the development of new methods, suitable for the permanent purification of liquid crystals from ions.
To explore the intrinsic mechanisms of the electrochemical reactions of porous graphene oxide in situ, the single-nanowire electrochemical probe is an effective tool. Although graphene is usually used as an additive in active materials to improve the electrochemical performance, how graphene influences the electrochemical performance and reaction mechanisms of electrode materials is under dispute. To address these issues, researchers have explored single-nanowire electrochemical devices to investigate the capacitance, ion diffusion coefficient, and charge storage mechanisms of graphene.
The drawbacks of existing measures for calibrating scanning probe microscopes (SPMs) based on various diffraction gratings and periodic microstructures, are large period and large error of period. Both factors prevent using these measures for precise calibration of SPMs and other instruments operating in the nanometer range. To address this issue, researchers have developed a method of calibration of a scanning probe microscope by lattice constant of a crystal.
Lithium (Li) metal-based batteries such as Li-sulfur and Li-air batteries have received considerable attention because Li metal can store 10 times more energy than graphite. However, there are safety and performance concerns for these types of batteries that arise from the formation of dendrites on the electrodes. To address this issue, researchers have proposed an unstacked graphene nanostructured lithium metal anode for lithium metal batteries to inhibit lithium dendrite growth and bring superior electrochemistry performance.
Our environment will slowly but surely evolve into an 'Internet of Things', where chips and sensors are integrated invisibly in the environment to assume their manifold tasks. Think of sensors that detect the presence of individuals and adapt the light in a building accordingly, resulting in serious energy savings. Those sensors will be, in a sense, the eyes, ears, and noses of our environment. At the recent ISSCC-conference, researchers have presented a number of remarkable developments. These may pave the way to a world where sensors assist us to drive more safely, live healthier, and make the planet more sustainable.