Stable Casimir Equilibria

To obtain more capabilities, devices are becoming smaller and smaller. Because nanostructures are sensitive to undesirable forces, managing force represents the biggest challenge in nanoscale mechanics. Quantum fluctuation induced electromagnetic fields result in attractive forces between closely spaced electrically neutral surfaces, called Casimir force. Between two surfaces of the same material, Casimir force is intrinsically always monotonically attractive, which results in disaster of unavoidable adhesion and friction in micro-/nano- machines. In my talk, I will focus on my recent theoretical and experimental demonstration of stable Casimir equilibia, where the Casimir force between two surfaces is repulsive at distances smaller than several tens of nanometers and attractive at large distances, so that the components in nanomachines can remain noncontact and stably trapped at a controllable distance.