Design and Application of Flexible Sensors in Human–Machine Interaction

Abstract

To improve the electrical conductivity, mechanical properties, and antibacterial properties of conventional hydrogels while simplifying their preparation steps for better application in wearable, flexible sensors and biomimetic electronic skins. Polyvinyl alcohol (PVA) hydrogels were doped with an ionic liquid based on zinc chloride to synthesize improved hydrogels using the freeze-thawing method. It is found that the addition of ionic liquid based on zinc chloride to the hydrogel resulted in a significant increase in electrical conductivity. However, an excessive amount of these liquids led to a reduction in their mechanical properties. The results reveal that the balance between conductivity and mechanical properties can be achieved by controlling the concentration of the ionic liquid based on zinc chloride. The higher the ionic liquid concentration based on zinc chloride in the composite hydrogels, the better the conductivity performance. The addition of an ionic liquid based on zinc chloride resulted in a significant improvement in the conductivity performance of the hydrogels. Furthermore, excellent mechanical properties are maintained even at a mass ratio of 1 : 10 between ionic liquids based on zinc chloride and PVA hydrogels, and composite hydrogels exhibit excellent antibacterial properties.