Using elastomeric membranes as dry resists and for dry lift-off

Elastomeric membranes that contained regular arrays of well-defined holes w ere formed by spin-coating a prepolymer onto a photolithographically define d master. These membranes were used as dry resists or as masks in dry lift- off to produce simple features as small as 5 mu m on both planar and nonpla nar surfaces. These procedures were "dry" because the membranes conformed a nd sealed reversibly to surfaces: no solvent was required either to deposit the membrane or to remove it from the substrate. A variety of materials, s ome of which would be difficult to pattern using conventional methods, were patterned using this technique. These materials included metals, sol-gels, hydrogels, biological macromolecules, and organometallic molecules. The me mbranes were used in sequential, dry-lift off steps to produce structures w ith greater complexity than those generated with a single membrane.