Template-free lithography for cross-scale channels towards enhancing nanofluidic devices

Abstract

Nanofluidic devices act a critical role in many inter-/multidisciplinary research fields including single-molecule DNA sequencing and (bio-) chemical detection because of their unique chemical and physics phenomena. Several template-assisted lithography techniques have been individually or synergistically applied to fabricate channels with nanometer to micrometer scales. However, realizing integrated fabrication of cross-scale channels with an atomic precision for emerging demand for device miniaturization and integration remains a significant challenge. Herein, channel with single atom layer depth, which was regarded as ultimate precision of silicon manufacturing, was realized using mechano-chemical scanning probe lithography. From atom- to micro-scale, the channels with hybrid features were also achieved, which can meet the fabrication requirements for all components of nanofluidic devices. The involved selective etching mechanism was addressed based on the proposed dissolution model. The excellent applicability in the field of cross-scale fabrication was demonstrated by label-free enzyme detection using prepared nanofluidic device. This study can significantly promote the development of integrated fabrication and miniaturization for nanofluidic devices.