The northern pike is a twitchy fish—when startled it changes direction incredibly quickly. Professor Yahya Modarres-Sadeghi’s fluid-structure interactions lab has built a robotic northern pike that mimics this natural movement. The robot can accelerate 25 times gravity in milliseconds. This ultra-realistic rapid movement allows researchers in the department of mechanical and industrial engineering to observe how flexible structures like the fish interact with fluids like water, explains PhD student Todd Currier ’10.
Studying the robotic fish can help engineers improve hydrodynamic efficiency, but the lab’s end goal is to deploy the robotic fish as a camera-equipped autonomous underwater vehicle (AUV). “We want to use it as a marine observation platform so realistic that it will blend into the ocean environment to collect data without disrupting the marine life that lives there,” says Currier.
Currier took the robotic pike out of the tank for its first freshwater swim this summer. “It’s almost eerie how much it moves like a fish in the water,” he says. “With this unobtrusive tool, we can get never-before-seen footage of the way fish behave when undisturbed.”
> Patricia Sullivan
There you are, full-throttle binge-watching your favorite television series of the moment, wanting only to forge on until the story arc plays out or your eyeballs melt, whichever comes first. Then comes the glitch: the frozen screen, the pixel breakdown, the out-of-sync soundtrack. But buck up, sofa spuds: help is on the way, courtesy of doctoral student Kevin Spiteri ’15G and Professor Ramesh Sitaraman from the Laboratory for Internet-Scale Distributed Systems in the College of Information and Computer Sciences. They’ve written a paper that presents three algorithms that enable video players to play with fewer stalls and at higher quality, reduce video quality switches during playback, and respond faster to connectivity changes. The paper recently received the Excellence in DASH Award from the Association for Computing Machinery Multimedia Systems.