Basic Design And Preparation Of Flexible Sensor

The birth and development of flexible pressure sensor aims to make up for the deficiency of rigid sensor in the detection of irregular surface pressure signal,so that it can be attached to various irregular object surfaces.At present,there are few studies on integrated array sensors at home and abroad.Array sensors generally have problems such as low density and large volume.In this paper,nano acetylene carbon black,silver coated glass microspheres as conductive filler,107 silicone rubber as matrix material,through the graphic processing of aluminum foil as flexible electrode array,a high-density flexible array pressure sensor is designed and manufactured,and based on LabVIEW virtual instrument and STM32,an array pressure sensing detection system is built.1)A PET/AL film with a thickness of only 20 ?m was selected as the flexible electrode material.The flexible electrode array was prepared by a relatively simple screen printing process and hydrochloric acid etching process.The electrode lead is designed as the interface standard suitable for FPC socket,and the electrical connection is convenient.Finally,100 electrode units are integrated in 9cm2,and the minimum diameter of electrode is 2mm.2)The effects of carbon black,silver coated glass microsphere,gas phase silicon filling ratio and silicone rubber viscosity on the piezoresistance and relaxation time of conductive rubber were studied.A large number of experiments were carried out to compare these factors,and the results were continuously adjusted and improved.The results show that when using silicone rubber with 8000 c St viscosity as matrix material,filled with carbon black 5%,silver-plated glass microspheres 12%,and vapor silicon 1.5%,the pressure-sensitive layer has the best effect,with good pressure resistance in 0-7N pressure range and relaxation time 5s.3)Three packaging schemes of array sensor are proposed,and the implementation comparison of specific schemes is made.The results show that the double-sided adhesive tape with graphic design is used as the bonding material between the upper and lower electrodes and the middle sensitive layer.The thickness of the array sensor is about 0.54 mm,and the mutual interference between the array points is small.4)A STM32 single-chip microcomputer and CD4051 eight-to-one bidirectional data selector are used to build a sensor array signal acquisition and processing circuit.The upper computer is designed by LabVIEW to display the pressure data of the sensor array in real time.