Formation of uniform microspheres using a perforated silicon membrane: A preliminary study

This paper presents a new method to generate uniform microspheres with biodegradable poly(lactic-co-glycolic acid) (PLGA) material using microelectromechanical system technology. The general idea with this method is such that a liquid phase containing the dissolved microsphere matrix material reaches a continuous phase after a silicon membrane with micron-sized perforations, where microdroplets are formed. After the droplet is detached from the membrane, the solvent diffuses out of the droplets into a continuous phase leading to the formation of solid microspheres. The experiment was performed to verify this method with some promising result. It has been shown that with this method, about 90% of the microspheres are in the range from 1 to 2 μm, which seems to be better than the result obtained with other methods using glass or ceramic membranes. The microsphere with such a size range is useful for intravascular applications and pharmaceutical drug delivery with a slow release of the drug at narrowly defined rates.