In 1920, Serbian-born inventor Nikola Tesla designed and patented what he called a "valvular conduit": a pipe whose internal design ensures that fluid will flow in one preferred direction, with no need for moving parts, making it ideal for microfluidics applications, among other uses. According to a recent paper published in the Proceedings of the Royal Society B, the Tesla valve also provides a useful model for how food moves through the digestive system of many species of shark. Based on new CT scans of shark intestines, scientists have concluded that the intestines are naturally occurring Tesla valves. This story originally appeared on Ars Technica, a trusted source for technology news, tech policy analysis, reviews, and more. Ars is owned by WIRED's parent company, Condé Nast.