Researchers have successfully built rollable and transparent electronic devices that are not only lightweight, but also don't break easily. They managed to overcome two major challenges associated with the manufacture of flexible electronics: The temperature restriction of plastic substrates and the difficulty of handling flexible electronics during the fabrication process. The team rolled their transistor devices 100 times on a cylinder with radius of 4 mm, without significantly degrading their performance.
Researchers have now developed a simple high-throughput, one-pot procedure to prepare a series of nanocrystal inks that makes it a very attractive fabrication process for applications in a wide range of all-solution-processed, flexible, stretchable, and wearable optoelectronic devices. The proposed approach, which can easily be scaled up to 10g, is generic for various transparent conducting oxides as well as other oxides nanocrystal inks.
The use of copper as an alternative electrode material to silver would reduce the cost of conductive inks. Nevertheless, copper nanowire conductors face a serious bottleneck for future practical use in flexible and stretchable optoelectronics: although they are nearly as conductive as silver, this conductivity is not stable. Researchers have now demonstrated conductive copper nanowire elastomer composites with ultrahigh performance stability against oxidation, bending, stretching, and twisting. This material offers a promising alternative as electrodes for flexible and stretchable optoelectronics.
The space industry has a strong requirement to develop flexible electrostatic discharge protection layers for the exterior cover of satellites in order to protect the electronics of the spacecraft. A new study explores carbon nanotube-polyimide composite materials as a flexible alternative for the currently used indium tin oxide (ITO) coating, which is brittle and suffers from severe degradation of the electrical conductance due to fracture of the coating upon bending.
Most printed electronics applications rely on some kind of ink formulated with conductive nanomaterials. Researchers have now introduced a rapid and facile method to fabricate a foldable capacitive touch pad using silver nanowire inks. The team developed a technique that uses a 2D programmed printing machine with postdeposition sintering using a camera flash light to harden the deposited silver nanowire ink. resulting paper-based touchpads produced by direct writing with silver nanowire inks offer several distinct advantages over existing counterparts.
Researchers have demonstrated ultra-stretchability in monolithic single-crystal silicon. The design is based on an all silicon-based network of hexagonal islands connected through spiral springs. The resulting single-spiral structures can be stretched to a ratio more than 1000%, while remaining below a 1.2% strain. Moreover, these network structures have demonstrated area expansions as high as 30 folds in arrays. This method could provide ultra-stretchable and adaptable electronic systems for distributed network of high-performance macro-electronics especially useful for wearable electronics and bio-integrated devices.
As we are moving into an era of flexible and wearable electronic devices, one challenge that arises is an increased vulnerability to mechanical failure. Relatively small damages such as tiny cracks along the electrical conductive pathway caused by the bending, twisting and folding of such devices could easily cause the entire gadget to fail. Researchers have now demonstrated light-powered healing of an electrical conductor. They show that green light even with low intensity has potential to provide fast and repetitive recovery of a damaged electrical conductor without any direct invasion.
The flexibility required when fabricating flexible electronic components has led to the use of plastic substrates and different transfer techniques to fabricate flexible devices. However, one of the biggest obstacles to mass adoption of flexible electronics has been the incompatibility with industry's state-of-the-art silicon-based CMOS processes. Researchers have now developed a new process that can be used to reduce the thickness of the silicon substrate until the required flexibility is obtained. In new work, they demonstrate a flexible (0.5 mm bending radius) nanoscale FinFET on silicon-on-insulator using a back-etch based substrate thinning process.