Transparent paper-based triboelectric nanogenerator as a page mark and anti-theft sensor

The triboelectric nanogenerator （TENG）, based on the well-known triboelectric effect and electrostatic induction effect, has been proven to be a simple, cost effective approach for self-powered systems to convert ambient mechanical energy into electricity. We report a flexible and transparent paper-based triboelectric nanogenerator （PTENG） consisting of an indium tin oxide （ITO） film and a polyethylene terephthalate （PET） film as the triboelectric surfaces, which not only acts as an energy supply but also as a self-powered active sensor. It can harvest kinetic energy when the sheets of paper come into contact, bend or slide relative to one another by a combination of vertical contact-separation mode and lateral sliding mode. In addition, we also integrate grating-structured PTENGs into a book as a self-powered anti-theft sensor. The mechanical agitation during handling the book pages can be effectively converted into an electrical output to either drive a commercial electronic device or trigger a warning buzzer. Furthermore, different grating-structures on each page produce different numbers of output peaks by sliding relative to one another, which can accurately act as a page mark and record the number of pages turned. This work is a significant step forward in self-powered paper-based devices.     

Tribotronic transistor sensor for enhanced hydrogen detection

Hydrogen detection with a high sensitivity is necessary for preventing potential explosions and fire.In this study,a novel ZnO tribotronic transistor is developed by coupling a ZnO field effect transistor (FET) and triboelectric nanogenerator in free-standing mode and is used as a sensor for hydrogen detection at room temperature.Tribotronic modulated performances of the hydrogen sensor are demonstrated by investigating its output characteristics at different sliding distances and hydrogen concentrations.By applying an external mechanical force to the device for sliding electrification,the detection sensitivity of the ZnO tribotronic transistor sensor is improved,with a significant enhancement achieved in output current by 62 times at 500 ppm hydrogen and 1 V bias voltage.This study demonstrates an extension of the applications of emerging tribotronics for gas detection and a prospective approach to improve the performance of the hydrogen sensor via human-interfacing.     

新型机电转化纤维材料与自供能可穿戴技术

随着柔性可穿戴电子设备的高速发展,众多可穿戴电子产品已成为人们日常生活的一部分。摩擦纳米发电机(triboelectric nanogenerator, TENG)为有效解决供电难题提供了新方法。基于TENG技术,利用织物将身体运动转化为电能与传感信息,机电转化纤维(mechano-electric conversion fibers, MECFs)应运而生。MECFs能够在高效收集身体低频、不规则机械能的同时,确保舒适、透气、安全且耐用,实现了自充电供能和自驱动传感两大功能。MECFs催生了一个以人体为中心、自我维持的能量和信息供给系统。基于MECFs的工作原理,起电材料的选择与设计是影响MECFs性能的关键因素,MECFs的多维度结构设计进一步提升了其能量转换效率。目前,MECFs已经在智能生活中的广泛应用,特别是自充电供能和自供能传感。然而,尽管取得了显著进步,新型MECFs的发展仍然面临着诸多挑战。展望未来,在人工智能和物联网的加持下,MECFs将继续向智能化、个性化的道路迈进。     

Self-powered sensor for naked-eye detection of serum trypsin

Here, we report a device for the detection of the proteolytic enzyme trypsin, which is a biomarker for pancreatitis. The sensor is self-powered, easy to use, and signals the presence of trypsin via a light-emitting diode (LED) that is visible to the unaided eye. Assay time is ～3 h, and the limit of detection is 0.5 μg/mL, which is within the range required for detection of trypsin at levels signaling acute pancreatitis. The sensing mechanism relies on trypsin digestion of a gelled protein layer. Partial digestion of the protein layer permits hydroxide penetration and subsequent etching of an underlying Al membrane. Degradation of both the protein and Al layers exposes an underlying Mg anode and closes an electrochemical circuit that produces ～2.2 V. This is sufficient voltage to illuminate the LED. A logarithmic relationship is observed between the time required for LED illumination and trypsin concentration. The device is equally effective for trypsin dissolved in buffer or serum media.     

Self-powered sensor for trace Hg2+ detection

A self-powered electrochemical sensor has been facilely designed for sensitive detection of Hg(2+) based on the inhibition of biocatalysis process of enzymatic biofuel cell (BFC) for the first time. The as-prepared one-compartment BFC, which was consisted of alcohol dehydrogenase supported on single-walled carbon nanohorns-based mediator system as the anode and bilirubin oxidase as the cathodic biocatalyst, generated an open circuit potential (V(oc)) of 636 mV and a maximum power density of 137 μW cm(-2). It was interestingly found that the presence of Hg(2+) would affect the performance of the constructed BFC (e.g., V(oc)). Taking advantage of the inhibitive effect of Hg(2+), a novel self-powered Hg(2+) sensor has been developed, which showed a linear range of 1-500 nM (R(2) = 0.999) with a detection limit of 1 nM at room temperature. In addition, this BFC-type sensor exhibited good selectivity for Hg(2+) against other common environmental metal ions, and the feasibility of the method for Hg(2+) detection in actual water samples (i.e., tap, ground, and lake water) was demonstrated with satisfactory results.     

基于纳米材料与纳米结构的纳米电源研究进展

随着现代社会的发展和能源危机的来临, 探索和寻找新的能源材料, 开发新能源是人类的永恒课题。自2006年基于ZnO纳米线压电效应的压电式纳米电源问世以来, 又研制出多种基于纳米材料和纳米结构, 以及不同纳米效应的新型纳米电源。本文综述了近10年来, 人们在纳米电源领域的研究成果; 系统介绍了基于压电效应、摩擦效应以及石墨烯能带调控纳米电源的原理和特点, 为今后新型纳米电源的开发提供思路和参考。