Micro-origami: USC folds up micrometer-scale 'voxels' for drug delivery

Egypt has its great pyramids; the Information Sciences Institute has its microscopic ones

After starting the folds using magnetic forces, the structure is sealed using capillary action. Click here for more information.

Researchers at the USC Information Sciences Institute have demonstrated a way to manufacture miniscule closed containers that might be used to deliver precise micro- or even nano-quantities of drugs.

According to ISI project leader Peter Will, who is also a research professor in the Viterbi School of Engineering, the new technique, described in a paper in the Journal of Micromechanics and Microengineering, is a two-step process.

Voxel as initially fabricated (a), etched,(b) and ready for final folding (c) Click here for more information.

Part one is the creation of flat patterns, origami, of exactly the fold up shapes familiar to kindergarten children making paper pyramids, cubes or other solids, except that these are as small 40 micrometers (µm) on a side. (1 inch = 25,400 µm)

Instead of paper, the USC researchers created the patterns in polysilicon sitting on top of a thin film of gold, using a well-established commercial silicon wafer process called PolyMUMPs. The next step was clearing the polysilicon off the hinge areas by etching.

When the blanks were later electrocoated with permalloy to make them magnetic, the photomask used left hinge areas uncoated, to make sure they were the places that folded.