Large area assembly of patterned nanoparticles by a polydimethylsiloxane template

A technique in which a polydimethylsiloxane (PDMS) template is used to assemble silicon oxide nanoparticles is proposed herein. The PDMS substrate was first constructed in a series of casting steps and a copper mask was then made with a laser marking system. Silicon oxide nanoparticles were generated by a modified Stober method. A PDMS substrate covered by the copper mask was then coated with a metal Au layer via sputtering to form the PDMS template. Finally, the silicon oxide nanoparticles were spin-coated on the PDMS template. Because the PDMS template consists of highly hydrophobic PDMS and less hydrophilic Au patterns, the nanoparticles undergo a dual dewetting process on the PDMS template to form an annular distribution around the borders of the Au patterns.