Patterned Surface Energy in Elastomeric Molds as a Generalized Approach to Polymer Particle Fabrication
Samuel D. Oberdick, Gary Zabow
We present a generic fabrication scheme to produce polymer microparticles with engineerable, complex shapes. The polymer particles are made from a polyethylene-glycol based hydrogel using a polydimethylsiloxane (PDMS) based molding technique. A simple surface treatment is used to pattern the surface energy of the PDMS molds, engendering the recessed molds with a higher surface energy than the PDMS surface. The contrast in surface energy causes hydrogel precursor to wet only the inside of the molds, creating isolated particles after curing with UV light. This eliminates the formation of an interconnecting scum layer and allows for fabrication of well-defined, independent particles. A simple strategy for releasing the particles is also presented.