Application Research Of Low-pressure Micro-spraying Technology In The Preparation Of Flexible Sensors

With the continuous improvement of people’s living standards and health needs,as well as the continuous advancement of electronic technology,Flexible Electronic Technology has emerged and is expected to spark a new intelligent revolution.Flexible sensors are considered to have great application potential in the fields of human-computer interaction and smart wearables.The short response time,high sensitivity,and strong reliability of flexible capacitive sensors make them an ideal sensor technology,providing important support for the development and innovation of future intelligent systems.In this paper,the preparation method and preparation process of the flexible capacitive sensor are studied in detail.Firstly,in order to study the trend of the influence of atomization pressure and liquid viscosity on the outlet flow rate and pressure,this study established a low-pressure micro-spraying coating system based on the existing micro-spray valve and conducted system dynamic simulation.After the structural equivalent conversion of the micro-spray valve was carried out,the liquid and gas systems from the two-phase gas-liquid inlet to the nozzle outlet were dynamically modeled using bond graph theory.After modeling,the liquid circuit and gas circuit of the nozzle were simulated using Simulink,and the influence trend of inlet pressure and liquid viscosity on outlet flow rate and pressure was obtained,providing data reference for studying the dynamic spraying film formation process in the external flow field of the nozzle.Secondly,in order to simulate the external liquid film of the nozzle,the simulation of micro-spray particle deposition and film formation process was carried out.The 3D model of the nozzle outlet and external flow field was established and optimized.Based on the understanding of the key models of Fluent’s two-phase flow,the gas-liquid outlet velocity obtained in Chapter 2 was used as the inlet condition of the flow field,and relevant simulation parameters were set.Dynamic spraying process was simulated using Fluent’s dynamic grid technology,and the effects of atomization pressure,nozzle height and velocity on the dynamic characteristics of the dynamic micro-spraying film were studied.A relevant database was established to guide the implementation of specific film parameters.Then,in order to verify the accuracy of the simulation results and achieve the goal of improving the performance of flexible sensors by controlling the width and thickness of the electrode layer,basic experiments were carried out.The preparation of flexible electrode solution and silicone rubber film solution was carried out,and single-factor and multi-factor experiments of micro-spray coating of flexible electrode thin films were conducted.The comprehensive effects of atomization pressure,nozzle height and moving speed on film width and thickness were obtained,and a parameter adjustment table was obtained to guide the production of subsequent soft sensors.Finally,in order to solve some problems in the surface quality of flexible sensors during the preparation of the silicone gel layer,electrode layer,and formation,this study proposed a preparation method combining scraping and micro-spray coating in the sensor preparation process.After introducing the detailed preparation process,the soft sensor was prepared and some performance indicators were tested,which proved the advantages of the combination of scraping coating and micro-spraying in terms of sensor quality and preparation efficiency.