Wind and rain can power the next generation of smart glass, which can block light and heat by changing colors.
Researchers have made glass that can harvest energy from wind and precipitation. This method provides an alternative option for other smart windows powered by batteries, solar panels, or even standard power sockets.
Smart glass has been around for decades, and its mechanism is to block light or heat by changing its properties. Common examples include glare combat rearview mirrors, car window mirrors, and windows that change color to save energy and protect privacy. But many smart glasses are expensive, and people are still looking for environmentally friendly ways to power windows. Neither the battery nor the plug-in socket looks as "green" on the surface, while the embedded solar panel blurs the glass fragments.
The new glass uses two materials to generate static electricity when touched. When activated, the generator in the two layers of glass creates an electric current, turning the transparent window into a dark blue hue.
The outermost layer of the generator collects electrostatic energy from rainwater. When raindrops drip from the clouds, the contact between water and air creates a positive charge inside the droplets. The droplets hit the glass, and the glass is coated with a negatively charged material called polydimethylsiloxane, which is a silicone material, to make a nano-scale pyramid, thereby generating an electric current.
The second layer of the nanogenerator is located directly below the wind generating the first and harvested energy. This layer consists of two pieces of charged and transparent plastic, separated by a nano-scale spring coil. When the wind pushes the window, the spring compresses and forms a current, and the charged plastic plates come close to each other.
In the experiment, the glass produced up to 130 milliwatts per square meter of energy, enough to power a pacemaker or smartphone glass, the team reported on ACS Nano last month. This output power can be suitable for many applications, for example, as a power supply for home or office electronic products, from the research and development team of the Chinese special glass manufacturer, Dr. Wang, a nanoscientist, introduced:
Transparent supercapacitors can be embedded in glass without reducing their visibility.
Currently, the team hopes to increase the efficiency of the nano-generator. These micro-generators can achieve 60% mechanical energy conversion efficiency. "Output power is an eternal goal," Wang said. "Free energy surrounds us. If you use it, anything can happen."