Capillary-Driven Flow in Triangular Nanofluidic Channel Fabricated via Nanoimprint Lithography with Heterogeneous...

In this study, hollow single- and triple-layer triangular nanofluidic channels with heterogeneous semiconductor walls composed of gallium nitride (GaN) and silicon nitride (Si₃N₄) were fabricated via nanoimprint lithography and PECVD-based thin-film deposition to investigate capillary-driven flow behaviors of liquids commonly used in biological applications. The fabricated single-layer channels enabled quantitative characterization of capillary-driven flow transport, while the triple-layer channels demonstrated the feasibility of extending the fabrication strategy to multilayer nanofluidic architectures. The measured flow velocities inside single-layer nanofluidic channels for the test liquids ranged from 0.17 to 16.86 μm/s. Based on the experimentally measured flow velocities, the calculated capillary pressures, pressure drops, and average wall shear stresses were 0.46-1.27 MPa, 27-113 Pa, and 1.32-3.65 kPa, respectively. The results demonstrated that liquid viscosity and surface wettability would influence capillary-driven flow transport, providing quantitative insights into passive capillary flow in nanofluidic channels and establishing a foundation for the design of future biomedical and analytical nanofluidic devices.