Flexible Wearable Multi-function Pressure Sensor Based On Triboelectric Nanogenerator

With the increasing development of the society,the improving of medical level and rapid development of internet technology,health and information security attracted more and more attention.So far,the shortage of medical resources and the personal information disclosure event plagued people more and more.In terms of health,aging society is more and more serious and the number of all kinds of chronic illness population is increasing year by year,the hospital treatment could not meet the needs of their own health,and more equipment are needed to realize their own health condition monitoring for a long time in their daily life.In the aspect of information security,while people use the way such as password,U aegis and the encrypted to protect personal information,personal information still been stolen and disclosed on the Internet or other media.If the health condition of individuals could be continuously monitoring and take a unique way of authentication,the number of all kinds of chronic diseases will greatly reduce and personal information disclosure problem will decrease as well.Nowadays,parts of the wearable device could be used in the measurement of human physiological signals for detecting of human body's health condition.Because of the unique of individual biological characteristics,using for biometric authentication,the information will be hard to be stolen.However,the present wearable devices can not realize health condition monitoring and authentication at the same time.To this end,this paper made the following research:(1)Herein,this thesis focused on flexible wearable multi-function pressure sensor which based on triboelectric nanogenerator.The sensor mimicked eardrum structure,combined with single electrode triboelectric nanogenerator,using PTFE film,Nylon film,ITO film and PET substrate.Combining with thin film vibration modal characteristics of the sensor we analyzed the mode of vibration theoretically.Using the working principle of single electrode triboelectric nanogenerator we analyzed the electrical output characteristic of the sensor.COMSOL Multiphysics was used to simulate vibration characteristics of the sensor and the open circuit voltage.It was verified that the design of the sensor had a wide scope of work frequency band and good high frequency characteristics.(2)Analyzed and processed the noise of the sensor.The power frequency interference,myoelectricity drift,motion artifact noise and baseline drift of the sensor output signal were processed.By integrating an analog filter and digital filter,we processed the output signal of the sensor.A 10 Hz Butterworth low-pass filter and 45 Hz~1500 Hz Butterworth band-pass filter were used to decompose the pulse wave signal and throat sound signal.For quantitative differentiation,Euclidean distance(EM)was calculated to measure the difference among the different individuals' pulse waveforms,and the correlation coefficient was calculated to measure the difference among different throat sound signals.In the end,a biometric identification technology based on pulse waveforms and throat sound signal was developed.(3)The flexible sensor was fabricated.And a multi-function flexible sensing system was constructed for human body health condition monitoring and biometric authentication.The test results indicated that,the sensor had high sensitivity and wide dynamic frequency range,when the external pressure F < 0.92 N,the sensitivity of sensor reached 52.5 V/N,low pressure detection limitation was as low as 0.010 N,0.1 Hz to 3.9 kHz vibration frequency range could be measured when pressure changed.Validated,the flexible sensor could realize health condition monitoring based on pulse waveforms in a long time with self-powered;the flexible sensor could be used as anti-interference throat sound microphone,even in noisy environment,which also could realize throat sound signal acquisition and recovery;based on pulse waveforms and throat sound signal,the double-modal biometric authentication was realized by using a single sensor with high reliability.Under the condition of 100 tester samples,false rejection rate was 1%,the false acceptance rate was 3%,the accuracy rate reached 98%.Using a single sensor can realize the health condition monitoring,throat sound signal recovery,double-modal biometric authentication with multiple functions.