Injectable hydrogels for bioelectronics: A viable alternative to traditional hydrogels

Hydrogels, renowned for their outstanding biocompatibility, tunability, and mechanical properties akin to human soft tissues, have emerged as promising candidates across diverse domains encompassing biosensing, electronic healthcare, drug delivery, and brain-machine interfaces. However, conventional hydrogels face constraints related to size limitations and interface mismatches, posing challenges for precise applications. Injectable hydrogels, distinguished by their minimally invasive nature and precise positioning attributes, herald a new era in bioelectronics. This review navigates through the latest advancements in this swiftly progressing field, shedding light on key performance metrics, formation principles, material selection criteria, and varied applications of injectable hydrogels. Additionally, the article deliberates on the challenges and prospects in this domain, including endeavors to enhance electrical and mechanical properties, foster reusability of injectable hydrogels, and explore emerging trends such as integration with printing technologies for broader interdisciplinary applications.