Microrobot harvests power from metal surfaces without batteries

Fudan University’s paper-thin membrane enables medical microrobots to run for months on skin-like surfaces

Fudan University developed a paper-thin electrochemical polymer membrane for microrobot footpads that harvests electricity from metal, zinc, or silicon surfaces. A 3D-printed crawler prototype demonstrated 150 days of intermittent operation with over 10,000 steps—reaching 1 million steps during testing—while consuming approximately 2 grams of aluminum. The membrane operates between -20°C and 80°C and powers onboard LED and Bluetooth transmitters. However, the system requires manual replenishment of potassium hydroxide due to electrolyte degradation and cannot extract energy from inert surfaces like plastic, glass, soil, or organic tissue. It also needs a small supercapacitor to buffer power during dead zones.

This technology advances medical applications where persistent operation without battery replacements matters—such as wearable health monitors. By harvesting energy directly from compatible surfaces, it could reduce the need for frequent battery swaps in resource-limited settings. But its utility is constrained by surface compatibility and the manual replenishment requirement.

Next, researchers must solve the electrolyte degradation issue and expand surface compatibility. The technology remains in trial stages, with current applications limited to metal/silicon environments. For medical use, it would require testing on human skin—which the membrane cannot power—making this a near-term step toward longer-lasting medical devices rather than immediate abundance.

Source: New Atlas