Recent progress of biosensors based on thermoelectric effects for monitoring physical activity and environment monitoring

Thermoelectric (TE) materials and sensors have emerged as a frontier in health and environmental monitoring, offering a silent, simple, and reliable alternative to traditional power generation methods by harnessing waste heat into usable electrical energy. They also offer superior stability and longevity, making them ideal for long-term monitoring applications. Furthermore, when compared to other self-powered biosensors, TE sensors excel in their ability to operate in a wide range of temperatures and environmental conditions, providing a more reliable and consistent power source for sensor operation. This review delves into the recent advancements in TE-based sensors, highlighting their multifunctional capabilities in real-time health monitoring and environmental sensing. We explore the fundamental principles of TE conversion, including the Seebeck effect, and assess the performance metric, specifically the figure-of-merit (ZT ). The integration of TE materials with flexible and wearable electronics is discussed, emphasizing flexible materials for their high efficiency and mechanical robustness. Applications in self-powered wearable devices and internet of things (IoT)-integrated environmental monitoring systems are underscored, particularly in fire detection and personal health monitoring. Challenges in material limitations, miniaturization, and scalability are addressed, with a focus on future research directions to enhance the sustainability and longevity of TE sensors. This review provides a comprehensive overview of the development of TE sensor technology and its future trajectory, emphasizing the importance of ongoing research to address current challenges and realize the capabilities of these innovative devices.