| In recent years,multimode flexible sensors that can simultaneously detect multiple different physical characteristics of objects have attracted widespread attention due to their potential applications in soft robots and intelligent wearable devices.However,achieving simultaneous detection of multiple physical characteristics(multimode)and integration of these functions in a limited sensing space is always a challenge.In this paper,a new type of dual mode flexible sensor integrated with photoelectric structure and ionic liquids is proposed,which can effectively detect the stretching,bending,and combined deformation of objects.The main tasks include:(1)Based on the sensitive characteristics of photoelectric signals and ionic liquids,LED lamps and photodiodes were designed to encapsulate both ends of the flexible ionic liquid channel,forming a dual mode flexible sensor integrated by two sensing mechanisms(resistive and photoelectric).The two sensing mechanisms share the same geometric space,not only improving the spatial utilization of the sensors,but also avoiding interference between signals,effectively detecting the stretching and bending of objects,and decoupling their combined deformations.In addition,a preparation method of the sensor is described in detail.(2)The sensitivity characteristics of the sensor are analyzed by using the theory of light intensity loss and the variation law of the resistance value of a homogeneous conductor.At the same time,using COMSOL Multiphysic software to construct multiple physical fields to conduct finite element simulation of the two sensing mechanisms,and preliminarily explore their response characteristics.(3)In order to explore the single mode detection performance of the sensor,a signal acquisition circuit system was designed and a bending and tensile deformation experimental platform was built.According to experimental data,the sensor exhibits good consistency,a large range(100% stretch,0-90 ° bend),excellent sensitivity characteristics(light stretch: 3.64,light bend: 3.73,ionic liquid stretch 2.46,ionic liquid bend: 0.049),good linearity(maximum nonlinear error: 22.1%),low hysteresis error(maximum error: 4.07%)Good repeatability(maximum standard deviation for1000 loads,photoelectric: 0.03246 V,ionic liquid: 0.20601 k Hz).(4)In order to further explore the dual mode detection characteristics of sensors and achieve decoupling of combined deformation,a combined deformation experimental platform was designed.The sensitivity characteristics of sensor multimodal detection are discussed,and a deep learning method using a long and short memory neural network(LSTM)is used to decouple the combined deformation of the object to be measured,demonstrating a high prediction accuracy(goodness of fit: 0.998 for stretching,0.985 for bending).(5)In order to further verify the sensor detection performance and reflect its research significance,a wearable wrist sensing application architecture was designed,and a software system was built based on the Py Charm environment,which can achieve real-time data collection,deformation prediction,and visualization functions.The above research demonstrates the feasibility of the dual mode flexible sensor,which can achieve the detection and decoupling of stretching,bending,and combined deformation,and provide assistance for future researchers in soft robots or wearable devices. |
