Hydrogel-based soft bioelectronic interfaces and their applications

There are great differences in mechanical strength and interface chemistry between traditional hard and dry rigid electronic interface devices and wet and soft biological tissues, which can easily cause problems, such as poor contact, signal interference, low electrical signal conversion efficiency and toxic side reactions. These differences not only make the devices prone to delamination or even fracture in a dynamic environment but also seriously affect the accuracy, safety, and efficiency of electrical signal transmission, thereby affecting the stability and reliability of the implantable electronic interface devices. In general, hydrogels have the advantages of high water content, low modulus and good biocompatibility, which make them ideal interface materials for bioelectronics, and hence, they are also the current research hotspot in the field of bioelectronics. In this review, we discuss the (i) properties of hydrogels, (ii) classification and design criteria for hydrogel-based soft bioelectronic interfaces, and (iii) application of hydrogel-based soft bioelectronic interfaces. We hope this review would guide researchers in related fields.