Nikola Tesla, a Serbian-born inventor, invented and patent what he called a "valvular conduit". This is a pipe that ensures fluid flows in one direction with no moving parts. It is ideal for microfluidics, among other applications. A paper in the Proceedings of the Royal Society published recently shows that the Tesla valve is a useful model of how food flows through the digestive system of many shark species. Scientists have determined that shark intestines contain naturally occurring Tesla valves based on CT scans.Ars Technica. This article originally appeared on Ars Technica. It is a trusted source of technology news, analysis, reviews and other information. Cond Nast, WIRED's parent company owns Ars.Samantha Leigh, coauthor at California State University, Dominguez Hills said that "it's high-time that some modern technology be used to look at those really amazing spiral intestinales of sharks." We developed a new way to digitally scan these tissues. Now we can see the soft tissues in great detail without needing to cut into them.Tesla's innovative valve design relies on a series of interconnected, tear-shaped loops that are asymmetric and asymmetric. Tesla described the 11 flow-control segments in his patent application as consisting of "enlargements and recessions, projections or buckets that, while virtually non-resistant to fluid flowing in one direction other than surface friction, create an almost impassable barrier to fluid flowing in the opposite direction." A Tesla valve has no moving parts and is therefore much more durable to wear and tear from frequent operation.Tesla claimed that water would flow 200 times faster through his valve in one direction than the other, though this may have been exaggerated. In accordance with Tesla's design, a team of scientists from New York University constructed a Tesla valve that could be used to measure the flow of water through it in each direction at different pressures in 2021. Researchers found that water flowed about twice as fast in the preferred direction.However, the flow rate was a crucial factor. Although the valve was very resistant at low flow rates, it would become more difficult to operate. This could lead to turbulent flows in the opposite direction and "plugging" pipes with disruptive currents and vortices. According to Leif Ristroph, the valve works more like an electrical switch and can smoothen out pulsing flow, much in the same way that AC/DC converters transform alternating currents to direct currents. Ristroph suggests that Tesla may have intended this valve design, considering that he is best known for inventing the AC motor and the AC/DC converter.The Tesla valve now provides insight into the unique structure of shark intestines thanks to a team of researchers from three universities: CSU Dominguez Hills, the University of Washington, and UC Irvine.Sharks are apex predators and feed on many species. They are important in controlling biodiversity within the larger ecosystem. Spiral intestines are common in sharks. They have a variety of folds in their intestinal tissue. These include columnar, scroll and funnel-pointing to the posterior. These four types are often depicted in 2D drawings that are either splayed out in 2 dimensions following a dissection, or as slices through the 3-dimensional structure in 2D. Scientists don't have much information about the structure in place, so this isn't helpful.According to the latest paper, Japanese researchers created a 3-D model of micrographs from the histological sections of a cat shark species. This provided "a tantalizing glimpse at the anatomy of a scroll type spiral intestine." Adam Summers (Friday Harbor Labs at the University of Washington) and his coauthors thought CT scanning could be a similar technique. This involves taking multiple x-ray images and then combining them to create 3D images.
