Preparation And Performance Optimization Of Bio Based Flexible Triboelectric Nanogenerator

With the progress of science and technology,the development of the times,intelligent wearable,portable electronic devices and implantable systems have emerged in many places closely related to human life,and have also become an important direction of scientific development in the future.In these fields,sensors play an important role in sensing and acquiring all information and data in the natural environment.However,the traditional piezoresistive and capacitive sensors rely on disposable power supply.The volume of power supply limits its application.At the same time,the treatment of waste power supply is also a big problem.In 2012,Wang Zhonglin’s team proposed that the triboelectric nanogenerator is used to collect the micro mechanical energy in the environment and convert it into electrical energy.At the same time,triboelectric nanogenerator as a sensor has high sensitivity to micro signals,is easier to realize flexible integration,and can realize self-driving without additional power supply.It was widely attracted the focus of the people since inventedAfter years of development,triboelectric nanogenerator has been expanding and enriching its materials and forms.However,many common materials in the field,such as polytetrafluoroethylene and polyethylene terephthalate,cannot be completely degraded and are easy to release polluting chemicals,which will bring a huge damage to the environment.In recent years,the concept of sustainable development has been deeply rooted in the hearts of the people.Many people began to use renewable biomaterials to make nanogenerators to improve the environmental friendliness of material selection,producing low-cost clean electric energy and implantable nano devices that can be used in biological systems.In this paper,bio-based nylon and polylactic acid were selected as positive and negative triboelectric materials respectively.Various surface morphology films were prepared by tape casting film-forming,deionized water leaching and electrospinning to explore the influence of surface microstructure on the output performance of triboelectric nanogenerator.The experimental results show that the surface micro-nano structure of electrospunning fiber membrane is conducive to the accumulation of charge and has the best output performance.At the same time,the chemical properties of the material have not changed during the experiment.Then test the output performance of the device,the bio based triboelectric nanogenerator with 15μm thick fibrous membrane,contact area of 2cm×2cm,the output performance of triboelectric nanogenerator containing open circuit voltage,short circuit current and charge transfer can reach 79V,1.5μA and 6.7n C under the frequence of 3Hz and the force of 7.5N;matching the optimal impedance,when the external load resistance is 8mΩ,the output power of the device reaches 86mw/m~2.Finally,the stability and environmental adaptability were tested.The nanofiber film as friction material showed good breaking stress and elongation at break,which ensured the stability and durability of the device from the mechanical point of view;In 7200 working cycles and multiple independent measurements,the output performance of the device is constant and fluctuates in a small range;Under the ambient temperature and of 10～60℃and humidity of 30%-50%,the device has stable output performance and strong environmental adaptability.The application of bio-based friction nano generator to monitor the force application state of human hands shows good sensitivity,indicating its good prospect in the field of self-powered sensing.