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

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.