Microfluidic Patterning of Ceramic Microstructures

Abstract

Patterned ceramic structures composed of two different materials with a feature resolution in the micrometer range have been generated by microfluidic lithography. Micro-channels made of poly (dimethylsiloxane) (PDMS) were filled with well-dispersed suspensions followed by solidification upon solvent evaporation. The cross-inserted comb-type ceramic structures with 100 μm in the width were fabricated in a relatively large area of 2×2 cm² for Al₂O₃ and NiO. It was found that controls of suspension characteristics and its drying play an important role in determining pattern quality. Micro-channel filling was significantly influenced by viscosity and surface tension of suspension and interfacial interaction of suspension with surfaces of the substrate and PDMS. Once filled, a proper drying condition must be met. Otherwise, the micro-channels were disconnected due to capillary stress, resulting in an incomplete pattern generation.