Research progress in fabrication of nanofluidic channels and applications

Abstract

Nanofluidics is the study on the behavior of fluid flow in a nanoscale-confined channel with at least one characteristic dimension smaller than 100 nm. Nanofluidics can exhibit unique physical phenomena such as ultrafast water transport, surface charges control ion transport that cannot be observed at microscales or in bulk structures. A significant growth of attention in nanofluidics was achieved due to the representative phenomena and effects, which make them potentially useful in osmosis energy generation, nanofluidic diodes or transistors, desalination, biology, and other applications. In the past few years, the fabricating nanofluidic channels is burgeoning throughout the globe and can be widely used for energy conversion due to the rapid advancement of micro- and nanotechnology. This review mainly focused on the research progress of the nanofabrication methods of nanofluidic channels, including nanolithography, microelectromechanical system(MEMS) based techniques, nanofluidic channels based on nanomaterials, and other natural nanofluidic materials. The preparation methods including electron beam lithography, focused ion beam lithography, scanning probe lithography, extreme ultraviolet lithography, interference lithography, and sacrificial layer releasing were discussed in detail. The advantages and disadvantages of each nanofabrication method were pointed out. Following that, the recent application progress of nanofluidics from five aspects was summarized: in salt differenatial energy conversion, responsive ionic gate, sensors of ion detection, sensing of single molecules, and water desalination. Finally, the current challenges were discussed, and the fantastic opportunities and perspectives in the fabrication of nanofluidic channels were prospected, such as high cost, reliability and stability need to beimproved, etc.

Keywords

• nanofluidic
• nanochannel
• photolithography
• two-dimension material
• energy conversion