Overview

• Femtosecond-laser pulses etched nanoscale structures into tungsten to create ‘black metal’ that selectively absorbs solar wavelengths and reduces heat loss.
• A thin plastic cover on the hot side serves as a miniature greenhouse, limiting convection and conduction to trap more heat and raise temperature.
• On the cold side, laser-textured aluminum heat sinks double cooling performance by enhancing radiative and convective dissipation.
• Laboratory tests demonstrated a 15× power increase over previous STEGs, successfully powering LEDs at lower illumination levels.
• Published Aug. 12 in Light: Science & Applications, the study remains a proof-of-concept that requires scale-up and field validation for commercial use.