A self-powered wireless temperature sensing system using flexible thermoelectric generators under simulated thermal condition

Wireless Sensor Networks (WSNs) hold significant potential for condition monitoring, particularly in vehicle condition monitoring, where real-time data acquisition is critical. However, their widespread adoption is often hindered by challenges such as complex power wiring and high maintenance requirements. To address these limitations, this study proposes a novel self-powered WSNs system that harvests ambient thermal energy through thermoelectric generators (TEGs). The system features flexible thermoelectric generators (FTEGs) equipped with integrated cooling fins and electrodes designed to conform to irregular heat source surfaces commonly found in vehicle power cabins. An energy management system incorporating an LTC3108 chip and a supercapacitor ensures efficient energy harvesting and storage. At the core of the WSNs node, a high-precision temperature sensor combined with ZigBee communication technology enables reliable data acquisition and transmission. Experimental performance evaluation was carried out in a controlled laboratory environment utilizing simulated heat sources that emulate conditions within a vehicle power cabin. The results indicate that the FTEGs produced an output power of 1760 μW under natural convection conditions, with the heat source maintained at a temperature of 80 °C, corresponding to a power density of 117.3 μW/cm². The system operates in a low-power intermittent mode, achieving a conversion efficiency of 37.9 %. Temperature measurements exhibit an error of only 1 % compared to commercial K-type thermocouple sensors, highlighting the system's accuracy and reliability. These results underscore the feasibility of the proposed self-powered WSNs system for practical applications in vehicle condition monitoring, offering a sustainable and maintenance-free solution for real-time temperature sensing.