Innovative Wearable Electronics: Next-Generation Nitrogen-Doped Lutetium-Carbon Microspheres Composites for Robust Energy Harvesting

Small. 2025 Jan;21(1):e2407386. doi: 10.1002/smll.202407386. Epub 2024 Oct 30.

Abstract

In the quest to advance wearable electronics, this study presents a novel method using nitrogen-doped lutetium-carbon microspheres (N, Lu-CMS) for high-performance piezoelectric energy harvesting. The synthesis of N, Lu-CMS begins with the polymerization of sucrose, followed by the preparation of N, Lu-CMS metal complexes through the incorporation of lutetium (III) nitrate hydrate and thiourea, yielding a black powder product. The wearable electronic device is designed with a silicon rubber (SR) matrix, reinforced with 0D fillers such as N, Lu-CMS, or molybdenum disulfide (MoS₂). Mechanical testing revealed a significant improvement in compressive modulus, reaching 3.7 MPa (N, Lu-CMS) at a concentration of 3 parts per hundred rubber (phr). Electromechanical assessments demonstrated efficient energy conversion, while biomechanical analysis, including thumb pressing tests, showed a notable increase in output voltage, peaking at ≈285 mV (N, Lu-CMS) at 3 phr. This research provides a foundation for future engineering applications, particularly in electronic packaging for wearable electronics and smart devices, underscoring the significant impact of N, Lu-CMS in this emerging field. The surface power density achieved is 0.026 nW cm- 2 (N, Lu-CMS) and 0.0056 nW cm- 2 (Hybrid). Lastly, the conversion efficiency is 6.26% for N, Lu-CMS, and 1.05% for the hybrid system.

Keywords: biomechanical energy conversion; carbon microsphere; composites engineering; smart device integration; wearable electronics.