Search

Over the past several years, the development of triboelectric nanogenerator (TENG) has blossomed owing to many advantages such as the simple structure, high conversion efficiency and wide material selectivity. Currently, most of TENG devices are constructed with micro-structured surfaces using complicated manufacturing processes. Owing to the lack of high-volume manufacturing scalability, it still remains a bottleneck to apply TENG into the commercial products. In this work, we report the development of a novel TENG, which leverages on the regenerated, flexible, biocompatible, and highly transparent silk-fibroin as a triboelectric layer and can be deposited on a PET/ITO substrate (SF/PET/ITO) using a simple spray-coating process. The as-fabricated TENG exhibits a maximum voltage of 213.9 V and a high power density of 68.0 mW/m 2 as a result of the ability of losing electrons and rough surface rendered by the silk-fibroin. We further demonstrate that this generator can charge a capacitor (10 μF) to 4.5 V in 6 mins, and instantaneously light up as many as 100 commercial LED bulbs. We anticipate that the large-scale fabrication of silk-fibroin-based TENGs will serve as a promising system for electricity generation with an extremely low cost to commercial applications. [ABSTRACT FROM AUTHOR]

Traditional MEMS acceleration sensors have been well developed, but most of them require an additional power source to operate. Moreover, they are usually susceptible to limited mechanical shock survivability due to the dominant reliance on rigid materials such as silicon. Recently, with the advancement in flexible materials and nanogenerators, piezoelectric sensors have received increasing interests due to the distinctive property of electricity generation, caused by its structural deformation. In this paper, we demonstrate a novel triboelectric acceleration sensor with flexible structure that is not only self-powered without the need of additional power source, but also is durable in a wide spectrum of operating ranges. The sensitivity is measured to be 1.33 mV/(m/s 2 ) with 0.64% nonlinearity over the acceleration range from 0 to 6 m/s 2 , and the shock survivability of 15,000 g. We envision that our work provides a new train of thought to combine MEMS technology and flexible electronics for the development of sensors with high shock survivability and low power consumption. [ABSTRACT FROM AUTHOR]

Abstract: A simplified, cost-effective flexible micro-electronic-mechanical systems (MEMS) technology has been developed for realizing a temperature-sensing array on a flexible polyimide substrate. The fabrication technique utilized liquid polyimide to form flexible film on the rigid silicon wafer using a temporary carrier during the fabrication. The platinum thin film is employed as temperature sensitive material and 8×8 temperature-sensing arrays were micromachined on the polyimide, from which the silicon wafer carrier was removed at the end of fabrication. The platinum thin film temperature sensor exhibits excellent linearity and its temperature coefficient of resistance reaches 0.00291°C−1. Because of the effective thermal isolation, the flexible temperature sensors show a high sensitivity of 1.12Ω/°C at 10mA to the constant drive current. The flexible MEMS technology based on liquid polyimide enables the development of flexible, compliant, robust, and multi-modal sensor skins for many other important applications, such as robotics, biomedicine, and wearable microsystems. [Copyright &y& Elsevier]

Developing self-powered accelerometers with high sensitivity is vital for Internet of Things, wearable electronics and sensor networks. Triboelectric nanogenerators (TENGs) have been proved as an effective solution for self-powered sensing. Currently, the research on self-powered accelerometers based on TENG still lacks the applicable theoretical model. And most self-powered accelerometers also have relatively low sensitivity. In this work, a novel V - Q - a theoretical model is reported to develop a self-powered and high sensitivity acceleration sensor based on TENGs. Deduced by the established model, the output performance of the sensor can be derived from theoretical calculations. Guided by the calculations, an accelerometer based on the silk-fibroin TENG is fabricated. The sensor exhibits a high sensitivity of 20.4 V/(m/s2) when acceleration ranges from 1 to 11 m/s2, and a high-power density of 371.8 mW/m2. These experimental results show a good agreement with the theoretical analysis. The development of the sensor shows many application prospects including wearable alarming devices and vibration detection systems. This research provides an in-depth theoretical study on self-powered acceleration sensors based on TENGs and an efficient method to develop high sensitivity self-powered acceleration sensors, which will promote the application of TENGs in self-powered sensing. Image 1 • A novel V - Q - a theoretical model for a self-powered acceleration sensor based on TENGs. • Developed a self-powered and high sensitivity acceleration sensor based on the V - Q - a model. • The self-powered acceleration sensor exhibits a high sensitivity of 20.4 V/(m/s2) and a high-power density of 371.8 mW/m2. • Application prospects including wearable alarming devices and vibration detection systems. [ABSTRACT FROM AUTHOR]