Research On The Crack Sensor Based On Wave Wrinkle Microstructure

With the emergence of flexible and miniaturized electronic products at the present stage,the demand for sensors for intelligent applications has greatly increased.The performance of flexible sensors for stress sensing has been studied by many scholars at home and abroad.Crack sensor has attracted much attention because of its high sensitivity,but the application is limited because of the low stretching range.In this paper,an Au-PDMS crack sensor was fabricated by using Au layer with lower Young's modulus as its conductive layer in order to improve the stretching range of the crack sensor.The tensile and bending properties of the crack sensor were characterized and tested.However,the Au-PDMS crack sensor has limited improvement in the stretching range of crack sensor.Wave wrinkle microstructures were introduced to the field of crack sensor and a crack sensor based on the wave wrinkle microstructure was proposed,which had a higher stretching range with a high sensitivity.(1)The Au-PDMS crack sensor without microstructures was fabricated,and compared with the crack sensors prepared before,it had a larger stretching range and better tensile properties.Its tensile properties were as follows:the sensitivity of GF is 236.65 in the range of<6%;921.9 in the range of 6%<?<8%and 6285.1 in the range of?>8%.Bending strain:within 2.5%strain,the?R/R₀ of resistance is 9 and the sensitivity of GF is 408.3.(2)Comparing the electrical performance of the Au-PDMS crack sensor with the wave-like crack sensor,it was proved that wave wrinkle microstructure could significantly enhance the stretching range of crack sensor.Also,predictable cracks were generated when the sensor was stretched.The sensitivity of the wave-like crack sensor with 70%pre-stretching is GF?80(0%<?<30%),GF?380(30%<?<60%)and GF?2585(?>60%).(3)The finite buckling deformation theory was analyzed to discuss the influence factors of the wavelength and amplitude of the wave wrinkle microstructure.The electrical properties of the wave-like crack sensor were tested,and the performance were analyzed with theoretical analysis and simulation analysis.It is found that with the increase of pre-stretching,the stretching range of the wave-like crack sensor increases gradually with the sensitivity decreasing.The wave-like crack sensor has the advantages of wide stretching range,high sensitivity and simple fabrication,which indicates it has the potential to be used widely in many practical applications.Therefore,the wave-like crack sensor was applied to human motion detection,robot motion monitoring and weighing to realize human motion prediction and robot automation control.