Micromachined silicon structures for modelling polymer matrix controlled release systems

摘要: Abstract Physical models of polymer matrix controlled release systems were constructed by using silicon micromachining to fabricate miniature pore networks having features comparable in size those found the systems. The formed from pyramidal cavities, ranging 100–200 μm on a side and 70–140 deep, etched into wafer. Narrow channels connect adjacent cavities glass wafer was bonded onto form linear ∼1 mm long. loaded with an aqueous solution sodium fluorescein, solute concentration during diffusion network imaged video microscopy. time-dependent concentrations within pores fit Fickian model determine effective diffusivities for fluorescein networks. In initial experiment, change diffusivity as function connecting channel width consistent mathematical constricted Since these techniques permit production precisely defined virtually any geometry, micromachined provide useful physical microporous polymers. addition, extensions present may be new microfabricated systems, where desired kinetics could programmed millimeter-sized devices fabrication intelligently-designed structures.