Fengben Xi

Flexible Organic Tribotronic Transistor for Pressure and Magnetic Sensing

Flexible electronics has attracted enormous interest in wearable electronics and human-machine interfacing. Here, a flexible organic tribotronic transistor (FOTT) without a top gate electrode has been demonstrated. The FOTT is fabricated on a flexible polyethylene terephthalate film using the p-type pentacene and poly(methyl methacrylate)/Cytop composites as the conductive channel and dielectric layer, respectively. The charge carriers can be modulated by the contact electrification between the dielectric layer and a mobile triboelectric layer. Based on the fabricated FOTT, pressure and magnetic sensors have been developed, respectively, that exhibit great sensitivity, fast response time, and excellent stability. The FOTT in this simple structure shows bright potentials of tribotronics in human-machine interaction, electronic skins, wearable electronics, intelligent sensing, and so on.

Stretchable Triboelectric–Photonic Smart Skin for Tactile and Gesture Sensing

Smart skin is expected to be stretchable and tactile for bionic robots as the medium with the ambient environment. Here, a stretchable triboelectric-photonic smart skin (STPS) is reported that enables multidimensional tactile and gesture sensing for a robotic hand. With a grating-structured metal film as the bioinspired skin stripe, the STPS exhibits a tunable aggregation-induced emission in a lateral tensile range of 0-160%. Moreover, the STPS can be used as a triboelectric nanogenerator for vertical pressure sensing with a maximum sensitivity of 34 mV Pa-1 . The pressure sensing characteristics can remain stable in different stretching conditions, which demonstrates a synchronous and independent sensing property for external stimuli with great durability. By integrating on a robotic hand as a conformal covering, the STPS shows multidimensional mechanical sensing abilities for external touch and different gestures with joints bending. This work has first demonstrated a triboelectric-photonic coupled multifunctional sensing terminal, which may have great applications in human-machine interaction, soft robots, and artificial intelligence.

An alginate film-based degradable triboelectric nanogenerator

Alginate, as a natural linear polysaccharide derived from brown sea algae, has the advantage of low toxicity, good biocompatibility, and biodegradability, which has aroused wide interests in recent years. In this study, a degradable triboelectric generator based on an alginate film is presented. The calcium alginate film, which is prepared by a simple freeze-drying method and a crosslinking reaction, has a form of porous structures that are beneficial for triboelectric power generation. The fabricated TENG has a stable output performance with a maximum voltage, current, and power of 33xa0V, 150 nA, and 9.5 μW, respectively. The performances of the TENG were investigated at different thicknesses of the calcium alginate film and various concentrations of the sodium alginate solution, as well as the degradability of the film with different thicknesses and temperatures. In addition, the TENG was designed for harvesting water wave energy in a low-frequency range from 1 to 4 Hz. This study is promising to provide new insights to develop degradable and eco-friendly TENG based on ocean plants and expand the application range in blue energy.

Tribotronic bipolar junction transistor for mechanical frequency monitoring and use as touch switch

Tribotronics, a new field that involves the coupling of triboelectricity and semiconductors, has attracted great interest in the nanoenergy and nanoelectronics domains. This paper proposes a tribotronic bipolar junction transistor (TBJT) that incorporates a bipolar junction transistor and a triboelectric nanogenerator (TENG) in the single-electrode mode. When the mobile triboelectric layer slides on the device surface for electrification, a bias voltage is created and applied to the emitter junction, and then the base current from the TENG is amplified. Based on the fabricated TBJT, a mechanical frequency monitoring sensor with high sensitivity and excellent stability and a finger-triggered touch switch were developed. This work demonstrated for the first time a tribotronic device with simultaneously controlled voltage and current voltage/current simultaneously controlled tribotronic device, which has promising potential applications in micro/nano-sensors, human-machine interactions, intelligent instrumentation, wearable electronics, and other applications.Transistors: Triggered by touchA new type of transistor that is switched by movement could greatly enhance interactions between machines, humans and the environment. The transistor, developed by Chi Zhang and co-workers at the Chinese Academy of Sciences in Beijing, takes advantage of triboelectricity – the electrification of objects by friction, such as when a balloon is rubbed on clothes. Triboelectricity has recently enabled researchers to convert mechanical energy into electricity in nanoscale devices, but not in bipolar junction transistors until now. Zhang and co-workers connected a copper pad to the base input of a silicon transistor structure, and showed that they could switch the transistor on or off by either lifting or sliding a polymer film across the copper pad. The team have already used their ‘tribotronic’ transistor design to develop highly sensitive mechanical frequency sensors and a finger-triggered touch switch.