Electrical Energy from Stretching Yarn

by Emil Morhardt

Well, yarn, sort of. This yarn is made by twisting carbon nanotubes until they become so twisted that the coil up into a helical spring-like configuration. You can do the same thing with cotton yarn or string. When the South Korean researchers (Kim et al., 2017) put the coil into an electrolyte then stretched it what they got was electrical current. Not a lot, but these are small laboratory-scale experiments and what the researchers had in mind was generating small amounts of energy to power sensors, for example, sewn into a shirt or gloves that are stretched and released under normal activities, but that wouldn’t work very well if the subject had to be immersed in an electrolyte. Or would it? They tried immersing the device, which they call a twistron, into the Gyeonpo Sea off South Korea where the temperature was 13ºC (a chilly 55ºF) and the sodium chloride content was 0.31 M, a nice electrolyte solution. But instead of sewing the yarn into a diver’s wetsuit, they attached it between a floating balloon and a sinker on the seabed to see if they could harvest ocean wave energy. Yes! They got it to light up a green LED whenever a wave came by. Continue reading

Turning the Kinetic Energy of Everyday Movements into Light

by Nina Lee

What would happen if we thought of energy not as a resource to be saved up, but as a resource to be constantly created and used? Uncharted Play, the brainchild of Jessica O. Matthews, is a company that challenges the way our society values energy. Matthews is a Nigerian-American Harvard graduate, inventor, and CEO who was inspired to create alternative energy sources after an experience with her family in Nigeria. During her aunt’s wedding, there was a power outage- a very common occurrence- and diesel generators had to be used to supply energy. The generators were emitting toxic fumes that everybody but Matthews seemed to be used to. When she later returned to the United States and continued her education, she wanted to create a cleaner alternative to the energy sources her community in Nigeria were utilizing. Continue reading

Designing Energy Systems to Be More Like Trees

by Erin Larsen

A team of engineers at Ohio State University are looking to nature to redesign windmills. In a recent issue of the Journal of Sound and Vibration, OSU researchers reported that they have discovered new information about how vibrations pass through trees when they sway in the wind. They believe that this research can be used to design new tools for harvesting wind energy that look less like windmills and more like mechanical trees. Continue reading