For college student Olivia Lenz, people are “wasting” energy all the time just by swinging their arms or walking down the street. But what if we could capture that energy and use it to charge a small battery? To answer that, Lenz, along with team members Hannah Clevenson and Tanya Miracle, experimented with zinc-oxide nanowires aboard a special reduced-gravity aircraft at NASA’s Johnson Space Center in Houston as part of the agency’s Motivating Undergraduates in Science and Technology (MUST) project. Working under the mentorship of NASA engineer Tamra George, the trio discovered that low-gravity conditions alter the material’s shape and length, producing “new and improved” versions that make better batteries for space suits. In fact, the super-wires might even allow astronauts to harness their movements to power the suit’s electronics.
NASA creates short bursts of reduced gravity by putting a modified jet through a series of steep climbs followed by sudden dives, also known as parabolic arcs. Although zinc-oxide nanowires have been grown in several ways in the lab, little is known about nanowire growth in microgravity.
In addition to its capacity for energy storage, zinc oxide also has piezoelectric properties, which means it creates a charge when stressed.
In addition to its capacity for energy storage, zinc oxide also has piezoelectric properties, which means it creates a charge in response to physical strain like bending or twisting. Piezoelectric materials can harvest energy that is expended during routine tasks, resulting in compact, low-power backup energy sources for lunar or planetary missions. “[Plus,] it can allow members of the military out in the middle of nowhere to charge their electronics without needing the sun or a generator,” Lenz says.
Another upside? Zinc oxide is also inexpensive. And because it can hold up to 10 times the charge of lithium, zinc oxide could potentially produce smaller or longer-lasting consumer batteries. Adds Miracle: “The electric car industry could easily use this to their advantage.”