Fabrication And Application Of Stretchable Strain Sensor In Human Health Monitoring

With the rapid development of new-generation electronic devices such as bionic electronic skins and flexible wearable smart devices,people’s demand for comfortable and convenient personalized medical care is constantly increasing.Wearable strain sensors can sense various strain signals generated by human activities in real time to monitor changes in health status in a timely manner,and play a vital role in human health monitoring.In order to meet the needs of comprehensive monitoring of human health,strain sensors with high sensitivity and high stretchability need to be developed to effectively monitor small physiological signals and large-scale joint motion.However,achieving both high sensitivity and high stretchability is still a huge challenge for stretchable strain sensors.Here,we have prepared an ultra-sensitive stretchable strain sensor based on photolithography.Utilizing the huge differences in conductivity and stretchability of micro-patterned Au and SWCNT,high sensitivity and wide detection range can be achieved at the same time for full range monitoring of human health.The main research contents are as follows:1.Inspired by the spider’s sensing system,a stretchable strain sensor with both high sensitivity and wide range was designed by utilizing the large difference between Au and SWCNT materials.By simulating the slit organ of spider,a stretchable Au/SWCNT strain sensor with both high sensitivity and high stretchability was designed using Au/SWCNT composite material,and then a miniaturized stretchable strain sensor with a length of 10 mm and a width of 100 μm was successfully prepared by photolithography.2.The sensing performance of the stretchable strain sensor was systematically optimized and characterized through mechanical and electrical performance testing.The sensing range and stretchability of the strain sensor were optimized by adjusting the line width and the number of layers of carbon nanotubes.In addition,various aspects of the strain sensor’s performance have been fully characterized through various mechanical and electrical performance tests,proving that the sensor has many superior performances,including ultra-high sensitivity(GF 7.1 × 104 and 3.4 × 106),and broad detection range(100% strain),excellent durability(10,00 cycles),ultra-low detection limit(0.1% strain),and fast response(1.3 ms).3.The performance of the sensor in full-range human health monitoring has been thoroughly explored by attaching the stretchable strain sensor to various parts of human body.The experimental results showed that the strain sensor has high sensitivity(GF = 687)even under micro strain(0.5% strain),and can accurately sense small strain changes caused by human physiological activities.In addition,the strain sensor can effectively detect and distinguish various human activities,including large-scale joint motion.It proves that the Au/SWCNT strain sensor can ultrasensitive monitor human health in full range,showing its great potential as a wearable health monitoring device.