Self-healing triboelectric nanogenerators (TENGs) with flexibility, robustness, and conformability are highly desirable for promising flexible and wearable devices, which can serve as a durable, stable, and renewable power supply, as well as a self-powered sensor. Herein, an entirely self-healing, flexible, and tailorable TENG is designed as a wearable sensor to monitor human motion, with infrared radiation from skin to promote self-healing after being broken based on thermal effect of infrared radiation. Human skin is a natural infrared radiation emitter, providing favorable conditions for the device to function efficiently. The reversible imine bonds and quadruple hydrogen bonding (UPy) moieties are introduced into polymer networks to construct self-healable electrification layer. UPy-functionalized multiwalled carbon nanotubes are further incorporated into healable polymer to obtain conductive nanocomposite. Driven by the dynamic bonds, the designed and synthesized materials show excellent intrinsic self-healing and shape-tailorable features. Moreover, there is a robust interface bonding in the TENG devices due to the similar healable networks between electrification layer and electrode. The output electric performances of the self-healable TENG devices can almost restore their original state when the damage of the devices occurs. This work presents a novel strategy for flexible devices, contributing to future sustainable energy and wearable electronics.

No abstract

Recent advancements in electronics engineering require materials with the resiliency and sustainability to extend their life time. With this regard, we presented a sustainable multi-functional nanocomposites strategy by introducing dynamic imine bonds based polyazomethine (PAM) as molecular interconnects and Fe3O4-loaded multiwalled carbon nanotubes as electromagnetic (EM) wave absorbing units. Driven by the reversible dynamic imine bonds, our materials show robust spontaneous selfhealing with excellent healing efficiencies of 95 % for PAM and 90 % for nanocomposite, and an accelerated recovery under a moderate mechanical stimulus. By adding Fe3O4-loaded multiwalled carbon nanotubes, the hybrids show excellent EM wave absorbing properties with 50% increment on minimum reflection coefficient (-40.6 dB) than the reported value. We demonstrate a full degradability by decomposing a nanocomposite sheet of 100 mg in an acidic solution within 90 min at room temperature. The nanofillers and monomers after degradation can be re-used to synthesis nanocomposites. The testing results for recoverable nanocomposites show a good retention on mechanical property. This novel strategy may shed a light on the downstream applications in EM wave absorbing devices and smart structures with great potential to accelerate circular economy.

There are only a few reported methods by which the size and morphology of organic single crystals for high-performance organic field-effect transistors (OFETs) or other devices can be controlled. Here, a facile solution-processed antisolvent vapor diffusion method was employed to grow millimeter-length C60 single crystal microwires directly in solution. The size of the microwires can be controllably varied via the C60 concentration and/or the choice of antisolvent. OFETs fabricated from the as-produced microwires exhibit mobilities as high as 2.30 cm2 V-1 s-1. A clear relationship between the crystal preparation conditions and device performance is revealed whereby it is observed that the lower the evaporation rate of antisolvent and/or the higher the C60 concentration, the higher the device performance. Photodetectors based on our microwires give a responsivity that is an order of magnitude higher than those grown by drop-casting methods. This study provides a facile method for the crystal engineering of size-tunable millimeter-length C60 single crystals, and revealed the important influences of the antisolvent on the C60 crystal size and the performance of devices based on them. We believe that our processing approach can be further exploited for a broad range of other organic semiconductors to achieve desirable single crystal size and morphology and thus obtain desirable OFETs and photodetector performance.

No abstract