Vacuum-assisted microfluidic lithography of ceramic microstructures

The method to fabricate complex shaped micro-patterned ceramic structures has been developed. Vacuum-assisted infiltrating the suspensions to the micro channels generated by the contact of polydimethylsiloxane mold to the substrate enables simple micro patterning of ceramics with complex structures in a relatively large area in short time. The use of well-dispersed ethanol-based suspensions of solid loading similar to 20 vol% plays an important role in a successful pattern formation without defects. The current process, called microfluidic lithography, is applicable to the entire range of ceramic materials which can be processed to colloidal suspension with relatively low viscosity. It is demonstrated that the interdigitated ceramic structures with 50 pm in the width composed of Al2O3 and NiO on a Si substrate were fabricated in an area of 5 mm x 5 mm.