Three-dimensional shaping strategy via solidifying polygonal nanofluid drops

Manufacturing fine three-dimensional (3D) structures from mesoscale down to nanoscale is of considerable importance in multiple application backgrounds. Here, we investigate the freezing of a nanofluid drop whose contact line is pinned by a 2D wettability base pattern. A surprisingly rich variety of shape choices for the top plateau can be obtained for basic polygonal patterns, allowing us to control the out-of-plane shape of the frozen drop. To understand the morphology of such an edge-confined drop and its shape change during solidification, we assume that the drop is an assembly of multiple slices with varying contact radii and a shared axial. Each contact radius yields a corresponding top plateau size at a certain drop height, engendering a specific plateau shape. The ability to control the plateau of a frozen drop and the fundamental understanding of its formation shed light on an alternative 3D fabrication method.