It involves a self-healing membrane that acts as a reverse filter, blocking small particles and letting large ones through. The filter does not separate objects by size. Instead, it responds to an object's kinetic, or movement, energy.
Developed by mechanical engineers at the Penn State University, the membrane wraps around the object as it passes through, permitting the membrane to entirely self-heal over the top of the object passing through it. A smaller object is accompanied by lower kinetic energy due to its smaller mass, a larger object with a higher kinetic energy will pass through the membrane, while the smaller object with lower kinetic energy will be retained. The self-healing properties would also allow medical devices such as surgical tools to pass through while contaminants stay out. The research may also impact developing regions where there are sanitation concerns.