This project is investigating the potential of a molecularly thin (15 nm) silicon-based, nanoporous membrane material (pnc-Si) to serve as a switchable molecular filter in microfluidic applications. The thinness of pnc-Si membranes implies orders-of magnitude improvement in separation efficiencies and sample loss compared to any commercial membrane material. Exploiting the ability to chemically affix silicon with positive or negative charges, experiments will first measure diffusive transport of charged dyes in solutions of different ionic strengths and compare to theories of diffusion of charged species through counter-charged pores. The effects of charges on protein diffusion through membranes will be directly investigated by modulating solution pH around the isoelectric point of select proteins. Finally, the project will coat pnc-Si membranes with nobel metals and attempt to manipulate pore size and permeability through the active manipulation of membrane charge.
Broader Impact: Pnc-Si membranes represent the first modular molecular filters available for microfluidic systems and should allow active adjustment of pore sizes. This technology should enable an array of new microfluidic devices for small-scale separation and detection of molecular species. The project will develop systems for characterizing pnc-Si membranes and device prototypes in collaboration with undergraduates participating in the Biomedical Engineering Department's two-semester Senior Design course. Research programs will contribute to the Academy of Entrepreneurship program at Rochester's Jefferson High School by developing a short course on technology and entrepreneurship and 2) by providing mentored research positions for high school students.
