Design Of Micro-electrochemical Workstation For Sweat Glucose Detection

Wearable sensors for human vital signs have been mature and commercialized,such as ECG,blood oxygen.However,these sensors cannot provide physiological information about human metabolism at the biological molecular level.Sweat,as an important part of human body fluid,contains a large amount of information related to human metabolism.The analysis of sweat components can reflect a situation related to human health.Studies have shown that glucose concentration in sweat is positively related to the glucose concentration in blood.Therefore,as a noninvasive method,sweat glucose detection can be used to monitor human glucose and avoids pain and cross-infection compared with traditional invasive blood collection.Electrochemical sensor is one of the most rapidly developed sensors,which can detect a variety of biomarkers in human body fluid with different electrochemical sensing methods.Development of electrochemical sensing technology and electrode manufacturing technology have made wearable electrochemical sensors possible.Combined with the intelligent hardware circuit,a multifunctional and integrated micro-electrochemical workstation is designed to realize the continuous detection of glucose in human sweat.The micro-electrochemical workstation designed in this paper mainly includes three-electrode analog acquisition front-ends,analog-to-digital conversion circuits,power management circuits,embedded microprocessor and its peripheral circuits.Through modes selection and parameters setting,the micro-electrochemical workstation can provide multiple functions such as cyclic voltammetry scan,linear voltammetry scan,chrono current scan and step potential scan.Meanwhile,Kalman filter algorithm is used for data smoothing and processing.Compared with commercial electrochemical workstations,the cost of wearable sensor and the size of hardware are greatly reduced.The micro-electrochemical workstation has richer scanning functions,wider voltage scanning range,higher voltage scanning accuracy and current detection accuracy than others.Based on the principle of enzyme-free glucose detection,a multi-step potentiometric method is designed to detect glucose in sweat with smart phone.Using the Bluetooth of n RF52840 MCU,real-time detection results can be transmitted wireless to mobile phone.Besides,three-electrode sensor based on electrochemical plating technology and the micro-electrochemical workstation are integrated on the same circuit board and designed as a wearable bracelet.Linear range of the sensor is 0-4 m M,and the regression equation is:4)()=-15.8126-9.810(8)),R~2=0.9920.The wearable bracelet has the advantages of simple use,convenient operation and high accuracy.