A revolutionary new design has produced an “electricity generator that draws power from water evaporating into the air.” It already has a practical application in the real world. “The power was enough to run a small LCD display, showing it is sufficient to power low-power gadgets.”
Design breakthrough
Researchers at The Chinese University of Hong Kong came up with a design breakthrough. “Unlike conventional hydrovoltaic systems that rely on mechanical intermediaries, the new device harnesses evaporation directly to produce usable electricity.”
Professor Ady Suwardi and his team like to call their new technology “evapolectrics.”
This design, Professor Suwardi beams, “could pave the way for sustainable, battery-free electronics powered by ambient moisture.” His team has plans on the drawing board for a sweat powered biosensor to demonstrate future capabilities.
“Hydrovoltaics is a way to make electricity from water, specifically by tapping into the energy released when there is humidity change, evaporation, or when water moves around.”
He broke through the barrier of low power generation by eliminating a step in the middle of the process. Suwardi’s team came up with a design “that bypasses the mechanical step altogether.”
Their evapolectrics generator “uses nothing more than a soft water-retaining gel and a thermoelectric component.”
A neat stack
The core of the novel design is standard off the shelf porous polyvinyl alcohol. That’s basically “a spongy, water-loving material that absorbs and releases moisture steadily over time.”
Like the lining for diapers. As water evaporates from the surface, it cools the gel.
“This creates a small but steady temperature difference between the cooled gel and a warmer base layer.” In between the heat sink base and hydrogel “is a thermoelectric generator, which converts the temperature difference into electrical voltage.”
It’s “built like a neat little stack,” Suwardi explains. At the top of their design “is a thin layer of PVA hydrogel, shaped to a small square and just a fraction of a centimeter thick in the most effective version.”
It packs quite a jolt. “The electricity power the device generated was more than three times higher than traditional hydrovoltaic systems,” co-authored Jing Cao of the National University of Singapore relates. Even better it works under “realistic ambient conditions.” That would be 79 degrees Fahrenheit and 40% humidity. With “a light breeze comparable to a slow walking speed.”
Cao is already taking out a few patents based on the design. “Imagine tiny sensors or wearable health trackers, like a fitness band, that run off the moisture in the air or your sweat, no batteries needed!“