Design And Preparation Of Artificial Skin Flexible Tactile Sensors And Sensing Characteristics

Skin is an important sensation of the human body's perception of the external environment,and human beings rely on the skin to sense the tactile perception of the surrounding environment.In this paper,a liquid core PVDF fiber(LPF,Liquid Core PVDF Fiber)was embedded in the silicone rubber,and an artificial skin flexible tactile sensor(AS,Artificial Skin Flexible Tactile Sensor)was designed and fabricated.The tactile sensing function,The theoretical analysis and experimental researches were carried out,and the preliminary research results were obtained.The main research contents and achievements are as follows:(1)The micro structure and mechanical properties of PVDF fiber were prepared by using self-made drawn fiber equipment.XRD test was carried out.The results showed that the higher the tensile modulus of the fiber is,the higher the piezoelectricity it is.The experimental results showed that the liquid PVDF fiber sensor signal was 1.75 times of the metal core PVDF fiber in the same experimental conditions.(2)A liquid core PVDF fiber was embedded in medical silicone rubber,and an artificial skin flexible tactile sensor was designed and fabricated.Using the energy method and the average charge method,the pressure sensoring model of this tactile sensor was established.The experimental results showed that the tactile sensor can sense different excitation frequencies,the sensor signals and the excitation signals had linear relationship.And can accurately reflect excitation processes of the impact wave,triangular wave and sine wave,the experimental results validated the theoretical model.(3)Based on the simply supported beam vibration theory,the sensitivity of this tactile sensor was studied.The sensitivity test was carried out with a piezoelectric micro-table.Under the action of sinusoidal excitation and shock excitation,the minimum response amplitude of the sensor was 300nm,the minimum response frequency was 0.1Hz and the resonant frequency was 7Hz.When the square wave was used as the excitation mode,the more obvious the impact characteristic of the square wave was,the stronger the signal was.The experimental results showed that this tactile sensor had a superior sensitivity to human fingers.(4)The liquid core PVDF fiber array were embedded in the medical silicone rubber,an artificial skin tactile sensor with a lot of LPFs was designed and fabricated.When the sensor was under sinusoidal excitation,It had the highest sensitivity when the frequency was 16Hz.When under impinging excitation,the distance between the excitation point and the fiber had a normal distribution relationship with the sensor signals.Using this model,the magnitude of the shock excitation and the impact point position can be accurately perceived.Through the theoretical analysis and experimental study,it showed that this artificial skin flexible tactile sensor had the characteristics of simple preparation process,low cost and high sensitivity.It has a wide range of applications and good prospects for development in the robot,rehabilitation medical and aerospace technology.