Seoul National University Researchers Develop Breakthrough Thin-Film Generator That Harvests Electricity From Human Body Heat

Seoul National University researchers create a flexible thin-film device that redirects heat flow to generate electricity from body heat without bulky batteries.

By: AXL Media

Published: Mar 18, 2026, 2:30 PM EDT

Source: Information for this report was sourced from Seoul National University College of Engineering

Overcoming the Thermal Conductivity Barrier in Wearables

A research team at the Seoul National University College of Engineering has announced a significant advancement in energy harvesting with the development of a flexible, thin-film "pseudo-transverse" thermoelectric generator. Led by Professor Jeonghun Kwak, the study addresses a fundamental flaw in existing wearable energy technology: the tendency for body heat to dissipate vertically through thin substrates without creating the temperature gradient necessary for electricity. Traditionally, these devices act like a sheet of paper, allowing heat to pass straight through into the air, which results in zero power generation. The new findings, published in the journal Science Advances, provide a structural solution that enables power production without requiring bulky or rigid components.

The Innovation of Redirected Heat Flow Architecture

The core of the breakthrough lies in a "dual thermal conductivity substrate" designed by the research team. By strategically incorporating copper nanoparticles into specific regions of a stretchable silicone substrate, the scientists created a single surface with alternating areas of high and low thermal conductivity. When placed against the skin, this architecture prevents heat from escaping vertically. Instead, the heat is forced to flow laterally along the high-conductivity paths. This redirection creates distinct warm and cool zones on the substrate surface, maintaining the vital temperature difference required to trigger the thermoelectric effect within a completely flat structure.

Structural Advantages Over Previous 3D Models

Prior attempts to solve the heat dissipation problem involved bending devices or engineering vertical, pillar-like structures to catch temperature differences. However, these methods significantly increased the volume and thickness of the hardware, making them uncomfortable for long-term wear. According to the research team, their "pseudo-transverse" approach maintains a low profile while achieving higher efficiency. This design mimics the traditional transverse thermoelectric effect but does so through a modular, printable film. This allows the generator to remain attached to the skin or clothing like a thin patch while continuously converting body heat into a usable electrical current.