Shih-Kang Fan
Associate Professor
Department of Mechanical Engineering
National Taiwan University

Manufacturing of three-dimensional (3D) architectures through assembly of (1) prepolymer hydrogel droplets with suspended cells/particles/molecules and (2) crosslinked building blocks with reorganized embedded objects is demonstrated on an electromicrofluidic platform. The complex and heterogeneous 3D architectures are in great demand in various applications, including in the construction of artificial tissues that recapitulate physiological functions by imitating biological structures and in the production of novel metamaterials with properties atypical or nonexistent in nature. 3D hydrogel building blocks with reorganized cells or particles are formed and assembled on the electromicrofluidic platform adopting electrowetting and dielectrophoresis. We demonstrate the manipulations of varied objects (a) in multiple phases such as prepolymer liquid hydrogel droplets and crosslinked hydrogels, (b) on a wide range of scales from micrometer cells or particles to millimeter assembled hydrogel architectures, (c) with diverse properties such as conductive and dielectric prepolymer droplets that are photo, chemically, or thermally crosslinkable, and (d) in adjustable geometries including discrete droplets and continuous liquid columns. 3D hydrogel architectures, composed of varied particles or cells reorganized in programmable patterns and biomimetic hydrogels of designed properties and in adjustable geometries, are obtained. The electromicrofluidic platform is general and alternative to manipulate cells and hydrogel for reconfigurable 3D architectures.