Kim, Nayeon Won, Jongin Mun, Yeongjun Kang, Yeong A. Kim, Hyun-Sik Kim, Jungwon Jang, Kwang-Suk 2025-10-30T07:00:26Z 2025-10-30T07:00:26Z 2025-10-30 2025-10 1944-8244 https://pubs.kist.re.kr/handle/201004/153370 In wearable thermoelectric generators (TEGs), the challenge is to develop thermoelectric materials that are both high-performance and mechanically flexible. Here, we present a flexible n-type Ag2Se/poly(vinylidene fluoride) (PVDF) composite film that simultaneously achieves enhanced thermoelectric figure of merit (zT) and improved flexibility. A freestanding Ag2Se film incorporating 5 wt % PVDF reached a zT of 0.591 at room temperature (versus 0.529 for pure Ag2Se) and a minimum bending radius of 3.5 mm (improved from 6 mm), and it maintained its performance over 1000 bending cycles. The performance enhancement is attributed to a uniform dispersion of PVDF within the Ag2Se matrix, which greatly reduces lattice thermal conductivity via interfacial phonon scattering. We integrated the n-type Ag2Se/PVDF and p-type single-walled carbon nanotube/PVDF films into a vertical wearable TEG architecture that leverages out-of-plane (through-thickness) thermal gradients. The resulting device generated power from a small skin-to-ambient temperature difference (similar to 10 degrees C) and exhibited significantly increased output under mild airflow or motion. This work demonstrates a viable strategy for harvesting body heat using flexible high-zT materials in a device design optimized for low-grade thermal energy. English American Chemical Society Wearable Thermoelectric Generators Based on Flexible Ag2Se/PVDF Films: Influence of Film Geometry and Wind on Energy Harvesting Article 10.1021/acsami.5c15434 1 ACS Applied Materials & Interfaces, v.17, no.40, pp.56359 - 56369 ACS Applied Materials & Interfaces 17 40 56359 56369 N scie scopus 001578841600001 2-s2.0-105018010359 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article TEMPERATURE SCATTERING COMPOSITE LEADS body-heat energy harvesting inorganic/polymer composites Ag2Se-basedfilms stacked film configuration bendable thermoelectric films