Researchers from Queen Mary University of London, the University of Warwick, Imperial College London, and Universitas Mercatorum have developed a stable, biodegradable Moisture-Electric Generator (MEG). The device is fabricated from gelatin, table salt, and activated carbon.

“Wearable, agricultural and environmental sensors increasingly require power sources that operate in humid settings without frequent battery replacement, particularly for skin-mounted patches and remote nodes that are difficult to retrieve,” said the researchers in a new study.

“Moisture-enabled electric generators (MEGs) can convert ambient and physiological moisture into electricity, but many systems rely on persistent polymers or complex architectures that complicate scalable, environmentally responsible deployment.”

According to the study published in Nano Energy, a single unit generates a continuous electrical output of approximately 1 volt for over 30 days by absorbing ambient moisture.

By connecting multiple units in series, the team scaled performance up to 90 volts and 5.08 mA, which is sufficient to power a 40-light LED string.

This approach transforms atmospheric moisture from an electronic limitation into a functional energy source. The MEG is manufactured using a water-based process and relies on widely available, non-toxic materials, offering a low-impact alternative to conventional batteries as global electronic waste rises.

Enables ion movement within the material

“Our goal was to rethink how electronic materials are designed and manufactured,” added Dr. Dimitrios Papageorgiou, corresponding author of the study. 

“This research demonstrates that high-performance energy devices can be made from low-cost, environmentally friendly materials. The ability of a gelatin-based system to generate meaningful electrical output highlights the scalability of this approach.”

As the gelatin-salt solution dries, it self-organizes into a three-layered structure. When exposed to humidity from the air or human skin, this architecture enables ion movement within the material, which drives the electrical output.

“Generating high voltages typically requires complex manufacturing processes or scarce materials,” said Dr. Ming Dong, first author of the study from Queen Mary University of London. “This work shows that it is possible to achieve strong performance using simple, sustainable components.”

In addition to energy harvesting, the material works as a skin-compatible sensor. Because its electrical output responds to small changes in moisture, the system detects physiological signals linked to humidity variations. 

Biodegrades safely after use

The researchers demonstrated that the device monitors breathing patterns in real time, detects speech through variations in exhaled moisture, and enables touchless proximity sensing. These capabilities allow the system to integrate into wearable health monitors and human-machine interfaces without requiring a battery.

Unlike conventional electronics that rely on plastics and heavy metals, the MEG degrades safely after use. The device biodegrades in soil within a few weeks or dissolves in water, allowing researchers to recover and reuse the components without hazardous chemicals. This design supports circular electronics, where materials safely return to the environment or recycling streams.

“By combining gelatin and salt, we have created a generator that operates using ambient humidity as its sole energy source,” concluded Dr. Dong.

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