Self-healing reverse filter opens the door for many novel applicationshttps://www.sciencedaily.com/releases/2018/08/180824150545.htmA self-healing membrane that acts as a reverse filter, blocking small particles and letting large ones through, is the "straight out of science fiction" work of a team of Penn State mechanical engineers.
"Conventional filters, like those used to make coffee, allow small objects to pass through while keeping larger objects contained," said Birgitt Boschitsch, graduate student in mechanical engineering.
She and the research team, however, developed the exact opposite, a stabilized liquid material that screens out smaller objects while allowing larger ones to pass through. The research was published today (Aug. 24) online in Science Advances.
The team experimented with liquids for their unique properties.
"If you put your finger in a glass of water and take it out, the water's surface self-heals," explained Tak-Sing Wong, the Wormley Family Early Career Professor and assistant professor of mechanical and biomedical engineering.
This newly developed membrane does the same, but unlike conventional filters, this one does not separate objects by size. Instead, it responds to an object's kinetic, or movement, energy.
"Typically, a smaller object is associated with lower kinetic energy due to its smaller mass," Wong said. "So, the larger object with a higher kinetic energy will pass through the membrane, while the smaller object with lower kinetic energy will be retained."
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