Fabrication of High-Aspect-Ratio Nanochannels using Novel Nanoscale Silicon Mold and Solvent Assisted Sealing
Y.H. Cho, J. Par, H. Park, X. Cheng, B.J. Kim, A. Han
Texas A&M University, US
Keywords: nanochannel, nanoimprinting, sealing
Abstract:Nanofluidic devices make it possible to isolate, manipulate and analyze single biomolecules such as DNA and proteins, essential processes in the emerging field of nanobiotechnology. Consequently, various nanochannel fabrication techniques have been developed to meet the increasing demand for nanofluidic devices. High-aspect-ratio (HAR) nanochannels are needed in applications requiring high flow rate in long nanochannels to prevent excessive pressure build-up. Previously, we reported the fabrication of a silicon dioxide nanochannel arrays using bulk micromachining without the need for nanolithography. Using this nanofabrication technique, we successfully fabricated HAR silicon nanoimprint molds and used it for HAR poly(methyl methacrylate) (PMMA) nanochannel fabrication. To create nanochannels out of these nanotrenches, the nanotrenches have to be sealed. We developed a solvent assisted sealing technique to create PMMA nanochannels. Owing to the HAR trench geometry, only the top sides of the channels were affected by toluene vapor sealing. This resulted in a nanoscale space at the bottom of the channel. In conclusion, we presented a novel PMMA nanochannel fabrication method based on the combination of anisotropic KOH etching of silicon, oxidation, nanoimprinting, and solvent assisted sealing. We expect that this simple nano-fabrication technique can provide means for low-cost and high-throughput nanochannel fabrication.