Dual-Plasticizing Strategy for an Enhanced Performance of Degradable Chitosan-Based Triboelectric Nanogenerators

Chitosan (CS), as the polymer friction layer of triboelectric nanogenerators (TENGs), has great potential for application in the development of degradable wearable sensors. However, its mechanical properties and output performance require further improvement. Although introducing plasticizers into polymers can simultaneously increase their mechanical properties and TENG output, this strategy remains unexplored for degradable polymer TENGs, which exhibit great potential as green materials in electromechanical conversion. Herein, we used glycerol and polyethylene glycol as plasticizers to enhance tensile properties and output properties of the CS TENG. Plasticizer incorporation resulted in an improved surface roughness and the introduction of numerous -OH groups, thereby improving the tribo-positive electrical generation of CS. The maximum open-circuit voltage can reach 173 V, which was three times higher than that of pure CS-based TENGs. Moreover, reduced Young's modulus of this film made it more advantageous for flexible sensor applications, and throat sensing and handwriting recognition were realized. Finally, the CS sensor exhibited antibacterial activity and complete degradability in soil within 36 days. Overall, this plasticizing method is expected to be extensively studied in the field of degradable, wearable polymer TENG sensors.