Self-powered Flexible Sensor Based On Superhydrophobic Hydrogel

Wearable flexible sensors have a wide range of application prospects in the fields of human monitoring,simulated robots,environmental monitoring,and electronic equipment due to their excellent force-electricity conversion capabilities.At present,there are many flexible sensors that convert stimuli such as strain and temperature into electrical signal changes such as resistance and capacitance.Most of them require an external power supply to continuously supply power for real-time monitoring,which affects the portability and long-term use of the sensor.In addition,sensors are easily affected by complex environments in practical use,so it is of great practical significance to develop a flexible sensor that can generate electricity by itself and work normally in complex environments.In this study,a superhydrophobic self-powered flexible sensor was developed with excellent self-healing ability,self-powering ability,human body monitoring ability,and ability to resist complex environment.In this paper,a combination of superhydrophobicity and self-healing was prepared by inserting superhydrophobic materials(modified carbon nanotubes and graphene)into the self-healing hydrogel in a semi-embedded state to prepare a superhydrophobic and self-healing hydrogel materials.The superhydrophobic hydrogel can still maintain excellent superhydrophobic properties under a strain state of 1058%,and can be healed within two hours at 70 °C after being fractured.The surface morphology of the superhydrophobic hydrogel was observed by scanning electron microscopy and X-ray photoelectron spectroscopy,and the mechanical strength of the superhydrophobic surface was tested.It was found that the surface energy of the superhydrophobic material was effectively reduced after modification.And can maintain good mechanical strength,good superhydrophobicity.The research further prepared a self-powered flexible sensor with superhydrophobic hydrogel as a flexible substrate,and performed a series of performance tests on the sensor.The test found that the self-powered flexible sensor can detect physiological activities such as human breathing,eye blinking,finger bending,wrist bending and raising head.It can not only convert the strain into a resistance change output signal,but also output the strain into a stable voltage and current signal while generating electricity,with excellent self-powered sensing performance.At the same time,the superhydrophobic surface can effectively ensure that the sensor can work normally in harsh environments such as humidity,acid and alkali,and dust,and has good environmental stability.In addition,the response speed of the sensor is also an important factor to measure its performance.The response speed of the sensor prepared in the study is only 0.2s.Comprehensive tests show that the superhydrophobic self-powered flexible sensor has good practical value.