Preparation And Application Of DGI Hydrogel Photoelectric Dual-mode Stress-strain Sensor

Stress and strain sensors can convert external stimuli into identifiable signals.This identifiable signal is not only a two-dimensional electrical signal,but also a visual optical signal.In order to achieve this visualization purpose,it is necessary to introduce visual color-changing materials into it.Compared to optical color-changing materials that require energy consumption,the reflected light wavelength of the responsive photonic crystal can be recognized by the human eye under external stimuli,and is an ideal low-power material.In this paper,a responsive DGI photonic crystal hydrogel was prepared using dodecyl glyceride itaconate(DGI)and used as a display material to construct a p hotoelectric dual-mode stress-strain sensor based on the DGI photonic crystal hydrogel.This stress-strain sensor has a response effect to external stretching and compression.In the response effect,it not only has a stable electrical signal output,but also can display the spatial position of the stimulus source through color change,and can be used in the field of pressure display and motion detection..First,this paper prepared a responsive DGI photonic crystal hydrogel,which was coated with silica gel as the dielectric layer of the stress and strain sensor,and assembled a new photoelectric dual-mode stress and strain sensor based on the DGI photonic crystal hydrogel.This stress-strain sensor not only has a stable electrical signal output,but also can display its deformation position in the form of color change.Under tension(0-113 %)and compression(0-33 kPa),the capacitance change of the stress-strain sensor is 50.4 % and 110.3 %,respectively.At the same time,the maximum emission wavelength can be changed from 615 nm(red)to 447 nm(blue)and 433 nm(purple).After undergoing 3000 cycles of stretching or 100 cycles of compression,the capacitance changes of the stress-strain sensor were 24 % and 110%,respectively.At the same time,when the stress and strain sensor is pressed and detects joint motion,it realizes the synchronous output of electrical signals and optical signals.Second,by introducing NaCl ions into the DGI hydrogel,a conductive DGI photonic crystal hydrogel was prepared and used as a conductive electrode to assemble a new type of spatially high-resolution DGI photonic crystal hydrogel photoelectric dual mode Stress strain sensor.This stress-strain sensor not only maintains the original sensing performance,but its color change is more obvious and the structure is more stable.During stretching(0-100 %)and compression(0-60.9 kPa),the capacitance change of the stress-strain sensor is 31 % and 44 %,respectively,and the maximum emission wavelength of its color changes from 624 nm(red)to 440 nm(purple).After the stress and strain sensor undergoes 15,000 cycles of stretching or 100 cycles of compression,the capacitance change of the stress and strain sensor is 21 % and 44 %,respectively.The stress-strain sensor can not only output electrical signals stably when pressed and to detect joint motion,but also rely on its higher spatial display resolution to make the human eye more clearly observe the spatial distribution of the stimulus.This design can enrich its application prospects in the field of display sensing.