As artificial intelligence, smart homes, and wearable devices become part of everyday life, the demand for steady, reliable power keeps rising.
Solar and wind energy are important solutions, but they depend on weather and sunlight.
Now, scientists at the University of Hong Kong have developed a new type of electricity generator that can produce power from something that is almost always around us: moisture in the air.
This new technology is called a moisture-activated electricity generator, or MEG. It does not rely on sunlight, wind, or moving parts.
Instead, it uses tiny amounts of water in the air to create an electric current. Until now, most MEGs only worked well in very humid environments and stopped working after a short time.
They also lost a lot of energy inside the device, making them inefficient and unreliable.
Led by Professor Dong-Myeong Shin, the University of Hong Kong research team found a way to solve these problems by creating a special type of gel.
This gel contains charged particles, known as ions, which can move back and forth.
The team designed the gel so that it contains different amounts of salt at different points inside it. This creates a built-in “concentration gradient,” or difference, that encourages the ions to move in one direction.
As moisture from the air is absorbed into the gel, it triggers the ions to flow, and this movement creates electricity. What makes this new material special is how stable and efficient it is.
The researchers found that it can produce useful amounts of power even when the air is quite dry.
It works well at humidity levels as low as 30 percent, which covers about 97 percent of the Earth’s surface based on global humidity data. This means it could be used in many climates around the world, not just in tropical regions.
Another big advantage is that the gel has very low internal resistance. In simple terms, this means very little energy is lost as electricity moves through the material.
Its resistance is similar to that of common electronic components, so it can directly power small devices without needing extra parts to manage the electricity.
Tests showed that the generator’s performance stayed stable for more than 50 days in normal indoor conditions, without noticeable decline. The team even used it to successfully power a smart window system that requires a high voltage to operate in a humid environment.
According to the researchers, this technology could open the door to a new kind of self-powered electronics. Instead of needing batteries or external power sources, future devices could run entirely on the moisture in the air.
This could be especially useful for indoor sensors, wearable technology, smart buildings, and other small electronic systems that need long-lasting, low-maintenance power.
By turning invisible water in the air into usable electricity, this new invention brings us one step closer to a cleaner, more sustainable energy future.
