Plant‐based Biomass/Polyvinyl Alcohol Gels for Flexible Sensors

Flexible sensors show great application potential in wearable electronics, human‐computer interaction, medical health, bionic electronic skin and other fields. Compared with rigid sensors, hydrogel‐based devices are more flexible and biocompatible and can easily fit the skin or be implanted into the body, making them more advantageous in the field of flexible electronics. In all designs, polyvinyl alcohol (PVA) series hydrogels exhibit high mechanical strength, excellent sensitivity and fatigue resistance, which make them promising candidates for flexible electronic sensing devices. This paper has reviewed the latest progress of PVA/plant‐based biomass hydrogels in the construction of flexible sensor applications. We first briefly introduced representative plant biomass materials, including sodium alginate, phytic acid, starch, cellulose and lignin, and summarized their unique physical and chemical properties. After that, the design principles and performance indicators of hydrogel sensors are highlighted, and representative examples of PVA/plant‐based biomass hydrogel applications in wearable electronics are illustrated. Finally, the future research is briefly prospected. We hope it can promote the research of novel green flexible sensors based on PVA/biomass hydrogel. In this review, the construction, performance indicators, properties and applications in the sensing field of selected plant‐based biomass and polyvinyl alcohol composite hydrogels are discussed.