Penn State Scientists Make Tiny Micro-capacitors for Measuring the Critical Casimir Force in a Simple, Well-defined Geometry

Recently, Moses Chan's Penn State group, including physicists Sarah Scheidemantel and Rafael Garcia, teamed with Electrical Engineering professor Srinivas Tadigadapa to create tiny capacitors with one flexible diaphragm electrode for measuring directly the critical Casimir force in fluids.

The critical Casimir force is due to the confinement of fluctuations in the fluid; its measurement provides a powerful probe of finite-size effects in fluid systems. The microscopic capacitors, with uniform gaps as small as 250nm and diaphragms as thin as 100nm, are being manufactured using state-of-the-art lithographic techniques. These nanometer dimensions allow for high precision determination of this Casimir force, which can be as small as 10-10 newtons near a variety of critical points.