DESIGN AND FABRICATION OF THERMOELECTRIC SMARTWATCH CHARGER

Abstract

This project focused on the design and fabrication of a thermoelectric smartwatch charger that converts body heat into electrical energy using the Seebeck effect. The objective was to design a compact and efficient power management system suitable for integration into wearable devices, particularly tethered smartwatches. Earlier research has demonstrated the feasibility of thermoelectric and hybrid energy harvesting for wearables, though challenges remain in efficiently converting very low input voltages. To address this, the study incorporated an ultra-low-voltage boost converter (LTC3108) to enhance energy extraction from minimal temperature differences. The materials used included a thermoelectric generator (SP1848), the LTC3108 converter, and a 2.7V, 20F supercapacitor for energy storage. Experimental evaluations were carried out under both controlled indoor conditions and natural outdoor environments to assess voltage output, efficiency, and charging performance. The thermoelectric generator produced voltages ranging from 0.015V to 0.027V, which were increased to about 1.0V by the boost converter during prolonged operation. The overall system efficiency was approximately 1.2%, demonstrating the viability of energy harvesting despite current limitations. The findings indicate that thermoelectric systems can serve as sustainable power sources for low-power wearable electronics, with potential for improved performance through better materials and increased thermal gradients.