Filtration of sub-100 nm particles using a bulk-micromachined, direct-bonded silicon filter

For successful size separation in biomedical applications, the filter used must meet several strict criteria. Not only must it have precisely-machined sub-100 nm pores (<5% variation), but it must also be able to handle large and small volumes with very high reduction ratios (>10(4)). In this paper, we will present a bulk-micromachined, direct-bonded silicon nanofilter that can remove particles as small as 44 nm. In doing so, we will describe the fabrication, the gas and liquid characterization, and the filtrations studies done on 44 nm and 100 nm beads.