A sustainable breakthrough in humidity electric generator technology
A new generation of energy harvesting technologies is emerging from research laboratories around the world. Among the most promising innovations is the humidity electric generator, an experimental device capable of converting naturally occurring water vapor fluctuations in the air into electrical energy.
The technology was not originally designed for large-scale power generation. Instead, humidity-based generators belong to the growing field of micro and mini energy harvesting, supporting the next generation of wearable electronics, distributed sensors and temporary devices such as biodegradable medical implants.
As these applications expand, the search for alternative power sources is becoming increasingly important. Traditional batteries often create sustainability challenges, particularly in disposable products where collection and recycling can be difficult or even impractical.
How a humidity electric generator works
Moisture-enabled electric generators (MEGs) are gaining attention thanks to their simple operating principle and the use of widely available, non-toxic materials.
The technology works by absorbing water molecules from the surrounding air through highly hydrophilic regions of the device. In wearable applications, moisture can also be captured directly from the skin.
This process releases ions and protons, setting them in motion. Because water is distributed and evaporates unevenly within the device, a concentration gradient forms, driving the charged particles in a single direction. When connected to an external circuit, this movement generates a continuous electric current. In many designs, chemical reactions at the electrodes help stabilize and extend electricity production over time.
A humidity electric generator made from gelatin, salt and activated carbon
Researchers from the Queen Mary University of London, University of Warwick, Imperial College London and Universitas Mercatorum have redesigned the conventional humidity electric generator to improve its sustainability profile.
Instead of relying on synthetic polymers, the team used food-grade materials including gelatin, table salt and activated carbon to create a device that is both stable and biodegradable.
The researchers employed a drying-induced self-stratification process. All materials were deposited together in a water-based mixture. As the film dried, the components spontaneously separated into two distinct layers.
One layer, composed primarily of gelatin and salts, absorbs moisture from the surrounding environment. The second layer, enriched with activated carbon, provides directional charge transport. This asymmetric architecture creates an internal pathway that promotes continuous water absorption and evaporation, sustaining a steady flow of electrical charges.
How much electricity can a humidity electric generator produce?
The newly developed humidity electric generator produced a stable and continuous electrical output of approximately 1 volt for more than 30 days.
By connecting multiple units in series, the researchers achieved scalable performance reaching 90 volts and 5.08 mA, enough to power small electronic devices, including a string of 40 LEDs.
The technology also demonstrated strong environmental credentials at the end of its lifecycle. Soil tests showed that the device degraded within a few weeks, while its components could also be recovered through a water-based recycling process involving dissolution and remolding.
“Our goal was to rethink how electronic materials are designed and manufactured,” the researchers explained. “This study demonstrates that it is possible to create high-performance energy devices using low-cost and environmentally friendly materials.”
The study, titled “A biobased moisture-electric generator with self-stratified architecture for physiological sensing and energy harvesting,” was published in Nano Energy in 2026 (DOI: 10.1016/j.nanoen.2026.112040).