Preparation And Application Of Antibacterial Breathable Hydrogel Based Electronic Skin

In recent years,flexible electronics are vigorously developing,and health has become a common life philosophy pursuit by everyone.Wearable strain sensors based on various flexible materials emerge as the times require.Among them,the Young’s modulus of hydrogel is similar to that of human skin,with excellent mechanical properties and high wearing comfort.It is an ideal material for preparing flexible strain sensors.However,for electronic skins that fit on the surface of human skin,breathability and antibacterial properties are critical to wearing comfort.Therefore,this work uses hydrogel as a base material to prepare a breathable and antibacterial wearable strain sensor,which realizes the in-situ monitoring of human joint movement and muscle micromotion,and built a real-time decoding and display system of Morse code and a wound rupture monitoring and early warning system.The specific research results are as follows:(1)Based on the microneedle template,a hydrogel-based electronic skin with a straight-pore air-permeable structure was prepared.This method is simple to operate,and can be widely used in various substrate materials.The size of the air-permeable pores is controllable,and the water vapor transmission rate reaches ten times that of the skin.The in-situ monitoring of human motion can be realized by attaching the sensor to each joint and muscle surface of the human body.(2)Nano-silver particles were selected as the antibacterial substance,while hydrazine hydrate was selected as the reducing agent.The in-situ reduction method was used to make sure the nano-silver was firmly anchored on the surface of reduced graphene oxide,and a hydrogel-based electronic skin with antibacterial ability was made.Nano-silver does not leak or aggregate,so the antibacterial effect of the hydrogel is more stable.(3)Combined with computer program,Morse code decoding and display system was built,finger motion signal was collected by electronic skin and the signal was input into computer,the signal combination of "dot" and "dash" is comprehensively determined according to the peaks and valleys of the signal and the slope of the changing signal by the prepared computer program,and the signal combination will be decoded to the corresponding letter according to the truth table as well.(4)A first-order high-pass amplifier is designed,and a wound rupture monitoring and early warning system is built in combination with the Arduino demo board.The system monitors the change of current flowing through the sensor in real time to determine the frequency of human body movement.Once the movement frequency exceeds the set threshold,the buzzer module will automatically send an alarm,thus help users reduce the risk of wound rupture.In summary,this paper uses hydrogel as the base material,and combines the actual needs to prepare a hydrogel with breathable and antibacterial functions.The mechanical and electrical properties were tested,and the air permeability and antibacterial properties were also tested,and a Morse code decoding and identification display system and a wound rupture monitoring and early warning system were built.The breathable preparation method and antibacterial preparation method proposed in this paper have wide applicability and can be compatible with a variety of flexible substrate materials.The two systems constructed also provide inspiration for the practical application of electronic skin.