Fabrication and Assembly Behavior of Square Microcapsules

Square microcapsules have been fabricated within porous silicon membranes. The capsules float in water when released from the membrane (see Figure). Dry capsules float with one of their edges pointing down, but after uptake of water, they float face down; the edge-down capsules assemble end-to-end while the face-down capsules assemble face-to-face.