Triboelectric Nanogenerators For Acoustic Energy Harvesting And Self-powered Sensing Of Human Motion Energy

With the rapid development of Internet of things(IoT),electronic devices have the characteristics of multi-functions,mobile and wide distribution.However,the multi-functions of electronic devices will inevitably need to use a large number of sensor networks.The utilization of traditional batteries to power sensors has many shortcomings,such as limited life and easy to pollute the environment and so on.Therefore,how to drive these sensors networks has become a major obstacle to the progress of Internet of things.In recent years,as a new technology of converting mechanical energy to electric energy,triboelectric nanogenerator(TENG)has shown a broad application prospect in collecting environmental mechanical energy,and has become an ideal way to solve this problem.Mechanical energy can be seen everywhere in our daily life,such as the movement of the human body,the vibration of air caused by sound waves and so on.Sound energy,as a kind of ubiquitous renewable energy,is widely distributed in every corner of the world.For example,factory-run machines,construction sites and airport aircraft take-off and landing processes produce a variety of sound energy almost every day.In this paper,a triboelectric nanogenerator integrated with tubular structure is proposed and implemented based on the efficient collection and utilization of acoustic energy.The sound-driven TENG can generate an open circuit voltage up to 400 V and a short circuit current of 175 μA under a sound frequency of 170 Hz and sound pressure of 115 dB.The electrical energy generated by the sound-driven TENG is stored in an energy management circuit and can be continuously supplied to a temperature and humidity meter with a rated voltage of 1.5 V.This work not only provides a simple,cost-effective arrroach for fabricating high performance TENG to recycle ambient noise energy into available electricity,but also enables self-powered electro-acoustic sensing applications,with potential applications prospect in artifical intelligence,IoT and enviromental noise reduction.With the development of Internet technology,smart wearable devices are used more and more widely.For example,smartwatch can be used to monitor the physical health and movement of human body in real time.However,these smart devices require replaceable or rechargeable batteries,while human movements are not effectively collected and wasted.Therefore,in order to reduce the use of batteries,it is necessary to develop a wearable generator that can be used to collect human motion energy to provide energy for these smart devices.In this chapter,a wearable TENG is designed based on silicon rubber and liquid metal,which can be used to collect the mechanical energy generated by arm swings and human walking.The TENG can produce obvious electrical signals when it is in slightly contanct with human fingers.Therefore,the TENG can be used to detect the momement of fingers,showing the potential to act as self-powered sensor.The TENG is expected to hava awide application prospects in the field of human-computer intercation,IoT,and so on.