A team of mechanical engineers developed a self-healing membrane that can block small particles and let large ones through.
The study published on Friday in the journal Science Advances described the stabilized liquid material that screens out smaller objects while allowing larger ones to pass through.
"Conventional filters, like those used to make coffee, allow small objects to pass through while keeping larger objects contained," said Birgitt Boschitsch, graduate student at the Pennsylvania State University and the paper's lead author.
This newly developed membrane does not separate objects by size. Instead, it responds to an object's kinetic, or movement, energy, according to the study.
"Typically, a smaller object is associated with lower kinetic energy due to its smaller mass," said the paper's correspondence author Tak-Sing Wong, assistant professor of mechanical and biomedical engineering at Penn state. "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."
Also, the membrane wraps around the object as it passes through, allowing the membrane to completely self-heal over the top of the object passing through it.
In its simplest form, the membrane can be created with water and a substance that stabilizes the interface between liquid and air, and has a structure similar to that of a biological cell membrane.
"You could add components that make the membrane last longer or components that allow it to block certain gases," said Boschitsch. "There are endless potential additives to choose from to tailor a membrane to the application of interest."
The researchers envision many creative, real-world applications for the membrane. If doctors need to perform open surgery without a clean operating room, this material could act as a surgical film to help replicate the clean environment needed to safely operate, according to them.
"The membrane filter could potentially prevent germs, dust or allergens from reaching an open wound, while still allowing a doctor to perform surgery safely," Wong said.