Electric eels could be new power source for medical devices

Knifefish are electrifying the imaginations of scientists searching for a new biocompatible power source. The fish, more commonly referred to as electric eels, emit a dangerous and powerful electrical shock as a defense and hunting mechanism.

Capable of stunning prey with a charge of up to 600 volts, the eels generate the charge with specialized cells called electrocytes in organs that run the length of their bodies. The squiggly fish's electrical capacity possesses characteristics that researchers say could perhaps be applied to power medical devices, leading to power sources that could have an edge over traditional batteries.

"It isn't as potentially toxic, and it runs on potentially renewable streams of electrolyte solution," Thomas Schroeder, a chemical engineer at the University of Michigan, told Nature.

To simulate how an eel's electrocytes are structured, Schroeder's team used four different hydrogels made of polyacrylamide and water, and stacked around 2,500 of these units together.

That generated about 110 volts, significantly less than an eel, whose cells are thinner and lower-resistance. However, even that amount may be enough to run low-power devices such as some cardiac pacemakers. The team is optimistic that with some tweaks to the hydrogel membranes, they can improve the system's performance drastically.

The team's findings were published in the journal Nature in December. MIT engineer Markus Buehler called their work "an exciting advance that transcends conventional thinking."

But 2017 was full of unconventional power source reporting here at Outliers, with stories on devices being run by sweat, solar power, gastric acid and egg whites. So electric eels? Seems like a natural.