Elasto-Capillary Manipulation of Freestanding Inorganic Nanosheets: An Implication for Nano-Manufacturing of Low-Dimensional Structures

Abstract

Ultrathin inorganic nanosheets (e.g., 2D nanomaterials, thin films, etc.) have attracted tremendous research interest because of their unique properties and promising applications. However, because of their ultrathin thickness (<100 nm) and low flexural rigidity, it is difficult to manufacture low-dimensional structures using these nanosheets. In this work, the observation of an intriguing elasto-capillary unfolding phenomenon is first reported which occurs on a variety of freestanding inorganic nanosheets floating on a liquid surface. Through theoretical modeling and experiments, it is demonstrated that one can easily unfold, re-roll, and transport different kinds of nanosheets by tuning the interfacial properties of the liquid. As a result, one can assemble nanosheets on the liquid surface into small structures (e.g., heterogeneous scrolls, optical resonators) and/or transfer them out of the liquid surface onto other surfaces for the manufacturing of flexible devices. The outcome of this research paves the way for nano-manufacturing of low-dimensional structures with ultrathin inorganic nanosheets.