The Fabrication And Applications Of Tough Hydrogel Bioelectronics

Biosensor is a kind of biosensor which is made of flexible conductive material or flexible substrate and can be fitted to human tissues to detect life activities.With the development of micromachining technology,such as carbon nanomaterials,metal nanomaterials and photolithography,the fabrication of flexible biosensors has been developed rapidly.However,these flexible conductive materials have some disadvantages,such as poor biocompatibility,expensive price,complex manufacturing process and so on.Hydrogel is a kind of polymer material which is closest to human biological tissue.Its water content is high,air and water can be diffused in hydrogel,and its biocompatibility is good.It can be prepared by means of light curing and heat curing.At present,hydrogel materials are considered by scientists to be one of the most ideal materials for making biosensors.CO₂laser engraving is a new method of making microchannels,which is cheap and easy to operate.The purpose of this study is to combine the polyacrylamide sodium alginate double network hydrogel and liquid metal,using double network hydrogel as the substrate of biosensor,and liquid metal as the conductive electrode of biosensor.Using carbon dioxide laser engraving method to achieve microchannel engraving,making a variety of patterns of biosensors.The research work is divided into the following three parts:1. preparation of hydrogel biosensors:Using polyacrylamide sodium alginate double network hydrogel as material for making chips,the fabrication of microchannels and the sealing of chips were realized by CO₂laser carving and two step solidification of hydrogels.Under the microscope,the structure of the valence channel was optimized,and the curing and carving conditions were optimized.2. Testing of mechanical properties and basic sensing properties of hydrogel biosensors:The tensile properties of hydrogel biosensors were tested,and the response of hydrogel biosensors to tensile strain,bending strain and distorting strain were tested.3. Applications of hydrogel biosensors in sound sensing,heart rate detection and wireless communication:The application of sound sensor:make a sound sensor that can be pasted on the throat of volunteers.Volunteers send out different sounds or different words with different volume,and verify the feasibility of the application through the response of sensor resistance to different sound stimuli.The application of heart rate detection:the heart rate detection patch which can be pasted on the heart of rabbits is made.The application of infinite communication:combining the infinite communication chip,using the hydrogel microchannel combined with liquid metal to make the antenna part of the wireless communication chip,and verifying that the wireless communication identity card can realize the wireless communication between objects.