Abstract
Thermoelectrics (TEs) convert waste heat into electrical power while enabling on-demand heating and cooling. Those attributes make TEs particularly appealing to satisfy the heterogeneous needs of wearables and the Internet of Things (IoT). However, current TEs are limited in terms of form factor and scalability. To address these limitations, this work demonstrates a scalable, flexible, and potentially reusable thermoelectric platform produced via the laser powder bed fusion (LPBF) of optimized n-type Bi2Te3 and p-type Bi0.5Sb1.5Te3 materials. These laser-printed materials exhibited high power factors exceeding 1200 μW m−1 K−2, resulting in a figure of merit (zT) greater than 0.2. When integrated into flexible planar devices, an output power of up to 70 μW was achieved at ΔT = 40 K for a footprint area of 8.3 cm2. The devices maintained electrical functionality under bending radii as small as 7.5 mm and withstood over 500 bending cycles. Designed for durability and recyclability, devices damaged by extreme bending could be partially reconditioned via hot pressing. Furthermore, the devices were easily disassembled into half-device modules, enabling straightforward separation and potential recovery of the printed materials. The versatility of the devices was demonstrated through the “active cooling fins” implementation, allowing efficient through-plane thermal harvesting on curved surfaces. This configuration could harvest up to 27 μW from the hot water pipe of a real heating system in ambient conditions. Additionally, rapid and reversible Peltier-driven cooling (~3 °C below room temperature within a few seconds) was achieved. This work highlights the potential of digitally manufactured, multifunctional flexible TEs for next-generation energy harvesting and thermal management in IoT nodes and wearable electronics.
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Data availability
The data supporting this study are available at the KU Leuven repository RDR https://doi.org/10.48804/RPBGCT under CC-BY-4.0.
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Acknowledgements
I.F. acknowledges the support of the Internal Funds KU Leuven, C1 project C14/21/078 and C2 project C2E/25/004. A.K. received funding from the European Union’s Horizon Europe research and innovation program under the Marie Skłodowska-Curie grant agreement No 101153244. Views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. V.N. acknowledges the support of Research Foundation—Flanders (Project No. 11K9223N). F.M.-L. and M.N.: the research was further supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program: grant agreement 948922—3DALIGN. This work was supported by Research Foundation—Flanders (project I011324N) via the medium-scale research infrastructure providing the PPMS equipment. The authors thank Stijn Vandezande and Daan Buseyne from the Department of Physics for their help with the Hall effect measurements. The authors thank Renaud Hendrik from Lubrizol for providing free Solsperse Hyperdispersants samples. The authors thank the support from the Materials Engineering Department: Wout Veulemans for advice in powder processing, Iris Cuppens for support regarding chemical experiments, Danny Winant for the liquid nitrogen supply, Joop van Deursen, and the workshop personnel for building the laser setup. The authors thank Dr. G. M. Velpula from the Department of Chemistry for his help with the KPM measurements.
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I.F. and F.M.-L. designed the experiments. V.N. performed FEM simulations. M.N. performed Raman characterization. I.F. performed the rest of the experiments. I.F., A.K., and F.M.-L. wrote the original manuscript. All authors reviewed and edited the manuscript. F. M.-L., A.K, and V.N. acquired funding.
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Florenciano, I., Naenen, V., Kaidarova, A. et al. Digital and scalable laser-based fabrication of reusable bismuth telluride thermoelectrics with superior performance and mechanical flexibility. npj Flex Electron (2026). https://doi.org/10.1038/s41528-026-00561-5
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DOI: https://doi.org/10.1038/s41528-026-00561-5
