Study On Flexible Tactile Sensor Based On Piezoresistive Effect Of MR Elastomer

Robot plays a very important role in industrial production and manufacturing,service industry,and daily life.Stability control and security interaction technology of robot is the key of robot application,it depends on the development of robot sensing technology.Flexible tactile sensing technology can promote the robot's supple control significantly and enhance the friendliness of human-computer interaction.Therefore,researches and explorations of flexible tactile sensing technology are significant to practical applications for the robot field.The shape of flexible tactile sensor to come is human skin,which is flexible and durable in physical property,available in sensing multiple dimensions,spots and parameters like temperature and humidity.Magnetorheological elastomer(MRE)is provided with stable conductivity and piezoresistive effect in flexibility status,and the adjustability of anisotropy MRE's conductivity is good.The application research and exploration of flexible tactile sensor whose sensitive material is made of anisotropy MRE provides valuable references.This paper points to designation and application of the tactile sensor.Begin with the study on deformation mechanics behavior,conductive mechanism and piezoresistivity mechanism of the material,then research and innovate in the sensitive structure,working principle,method to realize and the process of manufacturing,design and realize the circuit of sensor system at last.The major work of this paper are as follows:To find the material's reliable apply condition,mechanical properties of MRE is analyzed;Analysis MRE's conductive mechanism to figure out the suitable filling concentration at which the material has notable piezoresistive effect;Combined with mechanical properties and conductive mechanism,the piezoresistive effect theory of MRE is analyzed,and piezoresistivity equation is built.Select silicone rubber as the matrix and select carbonyl nickel powder as conductive filler,the sample of elastomer is prepared.The piezoresistive properties of isotropic and anisotropic magnetorheological elastomer was is tested and compared.The tested data is used to fit fill the piezoresistivity equation,to verify correctness of the piezoresistivity equation.With Flexible Printed Circuit(FPC)used as the electrode,an array sensor structure with 9 sensitive units is designed.The point-by-point detection of each sensitive unit is realized by using row scanning;Aim at the wide range of resistance variations of sensitive materials,this paper designs a graded resistance detection circuit which mixed series voltage divider circuit and constant current source circuit.Through the experiment,the sensitive structure is calibrated and the sensing system is tested,causes of the error are analyzed.At last,the feasibility of the flexible touch sensor based on MRE piezoresistive effect is assessed.