Charge Pump And Microswitch Enhanced Rotational Triboelectric Nanogenerator For Wireless Self-powered Metal Sensing System

With the development of electronic devices showing the trend of miniaturization,wearability,and portability,it makes the Io T technology closer to people’s lives.However,how to provide sustainable and distributed power for hundreds of millions of sensors in its terminals is a big problem to be solved.Using ambient energy is considered to be the most promising method to improve the survivability of sensor devices in different scenes.Among them,the triboelectric nanogenerator(TENG),as a mechanical energy collection device,shows great application prospects.However,the performance of TENG is determined by the surface charge density of tribomaterial,so chemical etching,ion implantation,and photo-etcing are often used to increase its effective surface-area and charge density.But these methods are expensive and technically complex,which has become one of the factors limiting their development.In addition,due to the inherent capacitance of the TENG,there will be a high output impedance.It is necessary to store energy first and then supply power in self-power sensing system,which makes The overall efficiency of TENG is extremely low and lost much sensing data.To solve the above problems,the research in this paper is as follows:(1)A combination of charge pumping strategy and micro-switch is proposed to enhance the performance of rotational TENG.At 200 rpm working frequency and 40% humidity,the output voltage is increased from 50 V to 400 V,which is about 8 times higher;the transferred charge is increased from 6.8 n C to 17.2 n C,which is about 2.5 times higher;the maximum load power is increased from 0.15 m W to 2.72 W,which is more than 18000 times higher;the best matching load is reduced from 50 megohm to 20 kΩ,which reduces about 2500 times.(2)A self-powered resonant sensing system based on TENG is designed by combining eddy current effect and LC resonant circuit.Compared with the conventional self-powered sensing circuit,it does not require a long time energy conversion,which enables fast metal detection With a sampling period of only 0.2 seconds.The sensing system can effectively distinguish metal products with a height difference falling within 25 mm and with a sensitivity of 14,000 Hz/mm.(3)Using the resonant sensor,a self powered wireless monitoring system for factory assembly line is built.The system uses laser as the wireless transmitting device and photoelectric detector for receiving.The wireless transmission distance is up to 2 meters.