Boosting responsive deformation of nanochannel membrane actuators by exploiting the surface defects

Abstract

The discovery of the “quantum tunneling fluid effect” in organisms has led to the exploration of constructing nanochannels for ultrafast transmission of ions or molecules, which is important for biochemical sensing, energy conversion, and mass transfer. Recently, responsive nanochannel membranes have been constructed by using 2D nanosheets and applied in the field of soft actuator fabrication. However, the response speed of these nanochannel membrane actuators (NMAs) is relatively slow compared to the ultrafast transmission of molecules within nanochannels. This delay can be attributed to the rate-limiting process of surface permeation. By increasing the surface defects on NMAs, the surface permeation process can be facilitated, resulting in improved response speed. In this study, we exploit the utilization of small active Laponite building blocks with a lateral size of 50 nm to induce more surface defects on NMAs. The resulting NMAs exhibit a rapid response speed of 175°/s (204 cm−1/s) upon the stimuli of acetone vapor. Furthermore, we employ direct laser writing (DLW) to create Origami creases on NMAs, enabling programmable transformations and expanding their potential applications in soft grippers, responsive electrical switches, and soft robotics.