Ionically Active MXene Nanopore Actuators

The authors present a coupled nanopore-actuator system where the thickness of an ultrathin free-standing MXene membrane is tunable through voltage-gated (de)intercalation of cations between MXene flakes. This reversible mechanical actuation of the membrane is detectable through changes in the ionic conductance of a single nanopore with a diameter of< 10 nm fabricated within the MXene membrane. AbstractReversible electrochemical intercalation of cations into the interlayer space of 2D materials induces tunable physical and chemical properties in them. In MXenes, a large class of recently developed 2D carbides and nitrides, low intercalation energy, high storage capacitance, and reversible intercalation of various cations have led to their improved performance in sensing and energy storage applications. Herein, a coupled nanopore-actuator system where an ultrathin free-standing MXene film serves as a nanopore support membrane and ionically active actuator is reported. In this system, the contactless MXene membrane in the electric field affects the cation movement in the field through their (de)intercalation between individual MXene flakes. This results in reversible swelling and contraction of the membrane monitored by ionic conductance through the nanopore. This unique nanopore coupled to a mechanical actuation system could provide new insights into designing single-molecule biosensing platforms at the nanoscale.
Source: Small - Category: Nanotechnology Authors: Tags: Research Article Source Type: research