MXene Empowers Recycled Chewed Gum for Bioelectronics and Wearable Sensors: Toward the Sustainable, High-Value Utilization of Waste

Growing resource scarcity and environmental urgency drive innovative strategies to transform waste into high-value materials for sustainable development. While chewing gum offers health benefits for oral hygiene and psychological well-being, its nondegradable polymeric composition creates environmental pollution when improperly discarded. Herein, chewed gum composites are fabricated by integrating MXene nanosheets into the gum through multiple stretching and kneading methods, realizing a superior electrical conductivity of 400 S m^–1 and excellent adhesion to various substrates. The resultant chewed gum with self-healing properties can serve as flexible sensors capable of detecting human movement, which shows its promising potential for wearable smart sensors. In addition, combined with the photothermal effect of MXene nanosheets, the composites exhibit highly efficient solar-to-thermal conversion and can be constructed as a thermoelectric generator with an output voltage of 135 mV when exposed to 1 sun illumination. Thus, this study not only provides insights into the versatility of chewed gum as applied in flexible electronics, wearable sensors, and energy harvesting but also offers promising potential for high-value utilization to address the environmental issue of chewed gum waste.