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 ∼50 nm and a depth up to ∼40 µm, 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.