Nanocrystalline Silicon Membrane for Molecular Filtration Innovation

1. MRI: Manufacturing of Nanocrystaline Silicon Materials at the University of Rochester, Philippe Fauchet and James L. McGrath, University of Rochester, DMR 0722653 The University of Rochester has developed a 15 nm thick, silicon-based nanoporous membrane material: porous nanocrystalline silicon (pnc-Si). Pores in the membrane form spontaneously as an amorphous silicon layer reorganizes into nanocrystalizes at temperatures above 750C. Porosities as high as 10% can be created and pore sizes can be adjusted between 2nm and 80nm by controlling the layer deposition conditions and the temperature profile during rapid heating and cooling. MRI funding has supported the purchase of modern instruments for deposition and rapid thermal annealing and are providing the development group with unprecedented control over membrane morphology. The silicon nanomembranes are revolutionary molecular filters because their thinness minimizes transport time and sample loss and because pore distributions provide for precise molecular discrimination. The silicon platform also allows the pnci-Si filters to be easily configured into formats that are convenient to particular applications. The image on the right shows the incorporation of a pnc-Si chip in a plastic housing that fits in standard laboratory centrifuge tubes. Pnc-Si membrane formats for microfluidics, cell culture, and drug screening arrays have also been developed with the new instrumentation.