Research On Ultra-flexible PDMS Composite Material And Application Of Flexible Pressure Sensor

In recent years,the Internet of Things and smart terminals have sprung up like mushrooms.As one of the most important components,sensors are gradually widely used in robots,wearable electronic devices and medical devices.Light and portable flexible electronic sensors with excellent electrical properties and high integration,making it gradually become a research hot spot in recent years.Researchers use a variety of clever ways to improve the sensitivity of sensors.However,these methods are complex and energy-intensive,which are not easy to fabricate in large area and limit practical application.Achieving flexible sensors with high sensitivity,fast response,low cost manufacturing and complex signal detection remains a huge challenge.Therefore,two new types of flexible pressure sensors are proposed in this paper.The theoretical models,manufacturing processes,sensing performance of the devices and related applications are systematically studied respectively.The main research contents are as follows:?1?Adjust the materials needed for the process to make a flexible sensor.The CCTO nanocrystals are prepared by electrospinning process.The filler multi-walled carbon nanotubes are prepared by Hummers strong acid oxidation.?2?The capacitive pressure sensors based on porous composite.The CCTO/PDMS composites are prepared by solution blending method.To explore the dispersion of CCTO with different concentrations in composite materials and the electrical properties.Porous composites with different porosity are prepared by mixing different concentrations of sodium chloride,and their mechanical properties are tested.The porous composites are encapsulated into a flexible pressure sensor with a sandwich structure for testing.The results show,the devices with different concentrations of CCTO have excellent linear response characteristics in the 0¹.3 kPa press range and maintain a stable output in 1000 cycles of compression and bending tests.Moreover,the device incorporating 3 wt%CCTO and 80 wt%NaCl has the highest sensitivity of1.68kPa^-1 and the response time of 30 ms in the pressure range of 0⁰.67 kPa.This device with high sensitivity and good stability can be applied to flexible wristband pulse measurement and achieve some good results.?3?The resistive flexible pressure sensors based on conductive elastic nonwovens.The corrugated elastic non-woven fabrics are repeatedly soaked in the carbon nanotube dispersion liquid to make the carbon nanotubes adhere to the cilias.In this way,the conductive elastic nonwoven materials are prepared.The conductive elastic nonwoven is finally encapsulated into a flexible pressure sensor.The test results show,devices soaked in carbon nanotube dispersion for 5 times show excellent linear response characteristics in the range of 0¹0 kPa.The sensitivity is 0.2 k Pa^-1 over a pressure range of 0⁵ kPa,and the output is stable at 1000 cycles of compression and bending tests.Based on the excellent performance of the device,itr can be attached to the surface of the finger to distinguish the different objects in the snatch.The sensor can be attached to the throat to acquire the waveform of the vocal vibration.In addition,this sensor can also be used for human pulse health testing.