High-Throughput Nanopore Fabrication and Classification Using Xe-Ion Irradiation and Automated Pore-Edge Analysis

Abstract

Large-area nanopore drilling is a major bottleneck in state-of-the-art nanoporous 2D membrane fabrication protocols. In addition, high-quality structural and statistical descriptions of as-fabricated porous membranes are key to predicting the corresponding membrane-wide permeation properties. In this work, we investigate Xe-ion focused ion beam as a tool for scalable, large-area nanopore fabrication on atomically thin, free-standing molybdenum disulfide. The presented irradiation protocol enables designing ultrathin membranes with tunable porosity and pore dimensions, along with spatial uniformity across large-area substrates. Fabricated nanoporous membranes are then characterized using scanning transmission electron microscopy imaging, and the observed nanopore geometries are analyzed through a pore-edge detection and analysis script. We further demonstrate that the obtained structural and statistical data can be readily passed on to computational and analytical tools to predict the permeation properties at both individual pore and membrane-wide scales. As an example, membranes featuring angstrom-scale pores are investigated in terms of their emerging water and ion flow properties through extensive all-atom molecular dynamics simulations. We believe that the combination of experimental and analytical approaches presented here will yield accurate physics-based property estimates and thus potentially enable a true function-by-design approach to fabrication for applications such as osmotic power generation and desalination/filtration.

Electro-osmotic Flow Generation via a Sticky Ion Action

“…Ion selectivity was purposefully engineered in solid-state nanopores by customizing the nanopore geometry, − by chemically modifying the nanopore surface, − and by introducing asymmetric surface charge distributions − or even mechanical strain . Although these synthetic solid-state nanopores do offer superior mechanical and chemical stability and are amenable to custom shape and charge modifications, , they usually have subpar spatial and temporal resolutions in biosensing applications, − suffer from pore clogging issues, and their fabrication remains relatively expensive.…”

Electro-Osmotic Flow Generation via a Sticky Ion Action

“…[23][24][25][26][27][28] , or even mechanical strain. 29 Although these synthetic solid-state nanopores do offer superior mechanical and chemical stability and are amenable to custom shape and charge modifications, 30,31 they usually have subpar spatial and temporal resolu-tions in biosensing applications, [32][33][34][35][36] suffer from pore clogging issues, 37 and their fabrication remains relatively expensive.…”