Crack-photolithography for mixed-scale micro/nanofluidic devices

Abstract

We describe an innovative crack-photolithography technique that utilizes a non-crystalized, monolithic, and organic material (e.g. SU-8 photoresist) using only on a standard photolithography process. This innovative technique can produce any desired nanopatterns on the surface of a micropatterned photoresist over large areas, with a high-throughput, and with no need for any specific nanofabrication techniques and equipment. Furthermore, the technique allows accurate control of the geometric dimensions of the nanopatterns, thereby resolving the limitations that previous cracking-based techniques were confronted by. As an practical application, we fabricated a microfluidic device that individually interconnected by a nanochannel array produced by the cracking and performed genetic induction assays for synthetic bacterial cells. The crack photolithography can produce such a complex nanofluidic device in single batch process with high reproducibility by soft lithography and with positioning of both the microchannels and nanochannels on the same surface, which is essential for a broad range of nanofluidic applications.