Development And Test Of Wearable Molecular Film Gate AlGaN/GaN HEMT Sensor

Over the past decade,wearable sensors have attracted much attention because of their great potential in monitoring wearer's health,fitness and surrounding environment.The flexible and solid wearable electrochemical sensor substrate has the advantages of being soft,thin,and deformable,and can be effectively adhered to the skin surface of the human body.The small solid-state sensor on the substrate has the characteristics of good sensitivity,high selectivity,simple and convenient,and fast detection.In recent years,such sensors have shown great application prospects in real-time monitoring of human body sign signals(such as blood pressure,heart rate,body temperature,etc.)and continuous rapid analysis of body fluid metabolites,and such sensors can transmit epidermal physiological information at the molecular level.Sense and sweat metabolite analysis provides rich chemical information.But in some wearable devices reported so far,ion-selective electrodes(ISE)and field-effect transistors(ISFETs)account for the majority,because they provide fast,inexpensive parallel sensing and ultra-sensitive label-free detection.However,long-term,repeatable detection is not possible,and the design of the Ag/Ag Cl reference electrode is complicated and the volume is too large,which prevents ISE and ISFET biosensors from becoming true wearable health monitoring platforms.This paper proposes a new wearable inspection platform based on AlGaN/GaN High Electron Mobility Transistor(HEMT).AlGaN/GaNHEMT processed by micro-mechanical(MEMS)processing technology,as a miniaturized,repeatable,and ultra-sensitive biosensor,has not been reported in a flexible and wearable sweat monitoring sensor.On this platform,the sweat belt is used to continuously collect sweat,and the p H detection unit and potassium ion detection unit are formed by modifying different sensitive membranes to realize long-term stable and repeatable detection of p H and potassium ions.Specific research content includes:First,we introduced the sensor of wearable sweat monitoring.Wearable sweat monitoring sensor generally needs to have good sensitivity,low detection limit,good chemical stability,good biocompatibility,good repeatability,miniaturization,and Integration and other advantages,leading to the AlGaN/GaN HEMT biosensor.1.Based on the working principle of the AlGaN/GaN HEMT biosensor,first designed the AlGaN/GaN HEMT biosensor platform structure for sweat monitoring,completed the process development for the production of wearable sensors,and optimized the lithography,etching,and coating,Annealing,packaging and other related process parameters.2.According to the working principle of the AlGaN/GaN HEMT biosensor,the specific structure of the sweat monitoring platform is designed,including the size of the AlGaN/GaN HEMT biosensor,the design of the two sensing units,the connection of the polyimide film,the sweat band Design,etc.,the wearable sensor has been developed,including photolithography,etching,coating,annealing,packaging and other related processes.3.Finished the surface modification of AlGaN/GaN HEMT biosensor,using atomic layer deposition(ALD)a layer of alumina as H~+sensitive film for continuous monitoring of H~+.A 5um thick K~+ion-selective membrane was made for continuous monitoring of K~+.4.Perform a performance test on the wearable sweat monitoring platform.And sweat is used for real-time monitoring.Experimental data shows that the wearable detection platform based on AlGaN/GaN HEMT has good sensitivity(p H 3-7sensitivity is 45.72?A/p H;p H 7.4-9 sensitivity is 51.073?A/p H;K~+Sensitivity is 4.94?A/lg?K~+),stability(28 days)and repeatability(relative standard deviation(RSD)of sensitivity at p H 3-7 is 2.6%,RSD of sensitivity at p H 7.4-9 is 2.1%,K~+sensitivity RSD is 7.3%).Our newly proposed wearable platform has huge potential in predictive analytics and personalized medicine.