Mechanism And Realization Of Robot Driving And Sensing Based On Hydrogel Additive Manufacturing

Hydrogel is a hydrophilic reticular polymer with excellent characteristics such as biocompatibility,flexibility,and ionic conductivity.Hydrogel devices（e.g.,hydrogel sensors,hydrogel actuators,etc.）prepared by using hydrogels as a critical site for devices and machines are widely used in drug transport,tissue engineering,biological research,and so on.At present,the fabricated devices with hydrogel as key sites have flexible robots,wearable devices,tissue glues,and so on,opening up a whole new and important field of technological research in biomedicine.Based on this,two types of hydrogel device construction strategies based on hydrogel driving and sensing are proposed for hydrogel microrobots and wearable hydrogel sensors,respectively,and the driving performance of the fabricated hydrogel microrobots and sensing mechanism of wearable hydrogel sensors are systematically studied to realize further exploration of the technological research and applications of hydrogel devices in biomedical fields.First aimed at hydrogel driving properties,the hydrogel photocatalytic microrobots with pore structure and adjustable pores were fabricated by 3D printing technology.The photocatalytic microrobot is able to achieve precise controllable propulsion under the excitation of visible light,and the presence of the pore structure in microrobots is able to improve the specific surface area and further enhance its driving performance.Secondly,currently in view of the microrobots are difficult to complete the propulsion in the high viscosity environment（blood,mucus,etc.）of biological fluids in vivo,the design and preparation of the microrobot based on hydrogel photothermal driving and effectively propulsion in the high viscosity environment（glycerol,more than 200 times the viscosity of blood）.The proposed photothermogel microrobot,under the excitation of NIR light,achieves an effective driving force in the high viscosity environment by generating instantly high propulsion through the hydrogel photothermal response,and provides ideas for the microrobots can really enter into living organisms to complete the design function.Finally,the PAM/SAP（polyacrylamide/SAP）composite water retention wearable ionic hydrogel sensor doped with a highly water retention functional resin sap is proposed for the sensing performance of the hydrogel.The sensing characteristics and mechanistic studies of the PAM/SAP water retention hydrogel showed its stable and well sensing performance at high work frequencies.The hydrogel sensor fabricated by using SAP/PAM high water retention hydrogel combined with convenient design circuit exhibited stretchable,sustained water retention,good durability and realized highly accurate tactile monitoring functions such as pressure measurement,direction judgment and sign recognition.