Self-Powered Optical Information Transmission System Based On Electret Generator

Since human society entered the age of electronics,various types of electronic devices have played an enormous role in all aspects of people's lives.However,these devices rely on external energy supplies and cannot work once they are powered off.To solve the specific problem of emergency communication,a self-powered optical information transmission system based on electret generator is designed and constructed in this paper.The system successfully realizes passive long-distance information transmission.The main research contents and results are as follows:(1)Select the arch electret generator as the power supply unit of the self-powered optical information transmission system,and establish the theoretical physical model of the generator.Use the COMSOL Multipysics finite element simulation analysis software to study the the potential distribution and charge flow under the circumstances of short circuit and open circuit.Furthermore,according to the established theoretical model,combining with the actual work process,we derive the output current expression of the generator,finding that the electret of bigger suface charge density will construct the generator with greater output current.(2)Comparing the surface potentials of four known excellent electret of polytetrafluoroethylene(PTFE),polyethylene(PE),polypropylene(PP)and fluorinated ethylene propylene copolymer(FEP),PTFE is selected as the material for the electret generator,according to the relationship between surface potential and surface charge density.The stable surface charge density of each film is calculated by measuring surface potentials of five different thickness PTFE films(30?m,50?m,70?m,100?m,and 200?m).It is found that the smaller the thickness of the PTFE film,the greater the surface charge density.In subsequent studies,a 30 ?m thick PTFE film is used to make an electret generator with excellent performance for an optical information transmission system.(3)The hardware circuit of the self-powered optical information transmission system is designed,and the relevant control program can be customized and written into the system conveniently.In this paper,we adopt the amplitude shift keying to encode information,transmited and displayed in a screen visually through the optical information transmission system.Furthermore,to achieve a complete self-powered optical information transmission system,an electret power management circuit and a DC boost circuit are designed to convert the pulse output of the electret generator into a stable DC output to provide energy for the signal receiving end of the optical information transmission system.