Massively-parallel ultra-high-aspect-ratio nanochannels as mesoporous membranes

Many fabrication technologies have been used to build nano/mesoporous materials/filters with a good size control, but the integration of these systems into a microsystem format has been a challenge. Microfabricated nanofilters suffer from small open volume and low-throughput. In this paper, we developed a novel fabrication strategy for generating massively-parallel, regular vertical nanochannel membranes with a uniform, well-controlled gap size of approximately 50 nm and a depth up to approximately 40 microm, by using only standard semiconductor fabrication techniques. The vertical nanofilter membranes were fabricated into an anisotropic nanofilter array, which demonstrates the ability to integrate nanofilters and micron-sized channels/pores seamlessly. We demonstrated efficient continuous-flow separation of large DNAs and small molecules in a two-dimensional vertical nanochannel array device. These ultra-high-aspect-ratio nanochannels have the advantage of large open volume, enabling high-throughput applications.