A Review of Functional Hydrogels for Flexible Chemical Sensors

Abstract

Hydrogels have drawn considerable attention in the field of flexible chemical sensors due to their unique 3D structure, high permeability, ion-conductivity, and tissue-like mechanical properties. These structures and properties allow them to be functionalized into diverse sensing components and respond to chemical signals in complex environments. Herein, an overview of functional hydrogel-based flexible chemical sensors is provided. First, the representative hydrogel materials are introduced and the operating principles for flexible chemical sensors are discussed. Then, state-of-the-art functional hydrogel-based flexible chemical sensing applications are highlighted including gas sensors, humidity sensors, pH sensors, glucose sensors, wound monitoring, and others. Finally, major challenges and opportunities in this field are provided.