Fabrication Of Reduced Graphene Oxide Based Pressure Sensor Using Lightscribe Technology

The traditional pressure sensor is based on silicon chip or metal strain,the rigid structure limits the pressure test of irregular topography,so the preparation of a flexible pressure sensor could be used for various topography surface pressure testing is very necessary.Graphene was widely used in the preparation of pressure sensor due to its piezoresistive effect and can be arbitrarily transferred to a variety of flexible substrates,however,because of the restriction of traditional graphene preparation methods and graphene properties,most of the reported pressure sensors are only in low range with high sensitivity,unable to meet the wide range pressure testing.This paper studied reduced graphene oxide preparation of wide range pressure sensor based on the LightScribe technology on the basis of predecessors' work.LightScribe technology reducing graphene oxide relative to traditional oxidation reduction technologies,short time consuming,low cost equipment,easy operation,and convenient for large-scale integrated on the flexible substrate.And through the XPS characterization of LightScribe reduced graphene oxide confirmed that LightScribe has very high reduction efficiency for graphene oxide.Optical microscope and AFM characterization results shows bump structure that different from traditional method prepared graphene formed after LightScribe process.And test found that Light Scribe reduced graphene oxide has piezoresistive effect,so the LightScribe reduced graphene oxide can be used for pressure sensor.From the analysis on the principle of Light Scribe this convex structure is related to the laser thermal effect in the LightScribe process,meanwhile is the main reason of generate piezoresistive effect.However,the LightScribe reduced graphene oxide has mellow structure,easily damaged,so need to add a layer of protection materials as pressure sensor,compare with the stability of the pressure sensor performance,using the tape/PET/PDMS as protection material,respectively,we find that PDMS is the most suitable protection material in this pressure senor,and the pressure sensors can measure up to 60 KPa pressure range with sensitivity of 0.00779 KPa^-1.In order to make the pressure sensor can satisfy the various conditions of pressure measurement,it's necessary to regulate the measurement range and sensitivity,for that designed and prepared different spiral turns of reduced graphene oxide,tested assembled pressure sensor performance founded that the more the number of coil,the lower the measured pressure range,and the sensitivity is increased with the increase of number of turns,the pressure range measurable can be as high as 800 kPa.Through the design of different density reduced graphene oxide graphics,a simple and effective control method of pressure sensor measuring range and sensitivity is found.Finally the recycling life test proves that it has more than 300 times working life with high stability,which is expected to be used in practical application.