Self-powered Wearable Oximetry Sensor Mask For Real-time Monitoring Of Pulmonary Disease Information

In recent years,portable and wearable electronic devices have been rapidly developing.With the promotion of flexible electronics,big data technology,and artificial intelligence technology,portable and wearable electronic devices have shown a trend of flexibility,integration,and intelligence.Lung diseases are one of the important health issues threatening human beings,and COVID-19 is currently one of the global pandemics.Non-invasive health monitoring of lung diseases is crucial,and by combining selfpowered piezoelectric nanodevices with wearable flexible electronics,a self-powered sensing system can be realized.This thesis proposes a self-powered wearable mask that can monitor and upload realtime exhaled oxygen information.The main components are tetrapod Zn O(T-Zn O)nanostructures and polyvinylidene fluoride(PVDF),which are combined with a flexible fabric substrate.The piezoelectric effect and gas sensing performance of T-Zn O/PVDF are coupled,and the sensing unit can convert respiratory energy into piezoelectric signals without any external power source.The piezoelectric voltage output by the sensing unit increases with the concentration of exhaled oxygen,serving as the sensing signal transmitted to the data processing module and wireless Bluetooth module to achieve realtime monitoring and upload of exhaled oxygen information to mobile devices.The main research contents include:(1)Zinc oxide nanowire arrays were prepared on a titanium substrate by hydrothermal method,which did not meet the requirements for integrating flexible sensors on the mask,and the structure of zinc oxide nanowires was unstable.The fourneedle-shaped zinc oxide has a stable structure with four supporting arms.By doping TZn O in PVDF,a sensing thin film unit can be made with good piezoelectric and gas sensing properties.The film structure is not ideal for gas-sensitive sensing,so PVDF doped with T-Zn O was coated on PP non-woven fabric with a fiber mesh structure,and then dried and cooled to make a flexible sensing unit.T-Zn O was fixed on the non-woven fabric fibers by PVDF,and the sensing unit was porous and loose,which was ideal for gas sensing.(2)The sensing unit produces changes in output piezoelectric voltage due to the adsorption of oxygen molecules and piezoelectric shielding effect.The piezoelectric effect of the sensing unit was tested to prove its stability.The response of the sensing unit was calculated by measuring the piezoelectric output at different oxygen concentrations.The sensing unit has sufficient sensitivity,with a response of 52.10% for 20% oxygen concentration compared to 10% oxygen concentration.The sensing unit was placed in the mask,and the oxygen consumption of the human body before and after exercise was measured,and the results matched those of the commercial oxygen concentration meter.The sensing unit can detect the decrease of oxygen concentration in exhaled gas.