100 nm Channels in Silicon
Our approach for nanochannel fabrication utilizes a Focused Ion Beam (FIB) microscope to modify conventional microfluidic devices for functionality on the nanometer scale. In the example shown below (image on the top) a micron scale fluidic network has been previously prepared by photolithographic etch in silicon. We have fabricated redundant 100 nm channels interconnecting two microscale fluidic pathways, using a focused Ga ion beam to selectively remove material with 10 nm resolution. Enclosed fluidic channels are subsequently achieved by bonding a transparent glass lid to the substrate. To test the transport properties of the nanochannels a fluorescent dye such as 25 mM Rhodamine B-base in a 10 mM sodium borate buffer solution is introduced and induced to flow in the fluidic network. The fluorescent signal in the redundant nanochannels (image on the bottom) confirms that we are able to drive flow between microchannels though the nanochannel pathways. Narrower features may be achieved though molecular coatings or oxidation of nanochannel walls.
J.P. Alarie, A.B. Hmelo, S.C. Jacobson, A.P. Baddorf, L. Feldman, and J.M. Ramsey, Fabrication and Evaluation of 2D Confined Nanochannels, in Micro Total Analysis Systems 2003, Volume 1, M.A. Northrup, K.F. Jensen, and D.J. Harrison, eds., Transducers Research Foundation, Cleveland Heights, Ohio, (2003), 9-12.
Imaging Electoosmotic Flow in
500 -50 nm Channels in Glass
Sealing buried nanochannels for DNA Sequencing Device Fabrication