Has the world’s next big electrical engine been in front of our noses all the time. It’s possible, according to new research published in Nature Materials which says that despite 10 percent of the Earth’s surface being covered by it, ice power remains untapped
Bending polycrystalline salty ice drives the flow of ions from one side to the other through small channels, generating an electrical current.
Every solid in the world exhibits some amount of electric response to being bent or deformed, called flexoelectricity, the report says. Most of these responses are far too weak to exploit — the world isn’t just a battery waiting to be tapped.
But when researchers turned to ice, a prevalent solid on Earth, and one of the most common solids in space, the story was different.
Adding table salt (NaCl) created a solid where every ice particle was surrounded by a few nanometers of briny liquid. When the salty ice was bent and unbent, this fluid sloshed back and forth, creating a current of ions that conferred a flexoelectrical effect around 1000 times larger than that of pure ice and on par with specially designed materials.
Salty ice has plenty of advantages in the real world, such as being moldable , non-toxic, and requiring no trace elements, as found in typical electronics. The simple solid could be incorporated into engineering projects in polar areas where sunlight is too low for solar power and water threatens soft robotics’ wiring and batteries, though it’s not a great candidate for deep space applications since the key briny liquid freezes at -70ºC.
In a related News & Views, materials scientist Daesu Lee writes that the work is important for “ reminding us that dramatic effects can sometimes be found in plain sight.”
