Noncontact fine alignment for multiple microcontact printing

This study proposed a method for the fine alignment of polydimethylsiloxane (PDMS) stamp used in multiple microcontact printing. The procedure of alignment method was organized into three steps; (1) the fabrication of PDMS stamp with an alignment marker, (2) the position detection of PDMS stamp with a noncontact laser displacement sensor on an automated planar x-y axes stage, and (3) the position adjustment of PDMS stamp to target position with another automated planar x-y-θ axes stage. The procedure was able to perform without contact onto the surface of PDMS stamp just before the moment of contact printing. Therefore, the surface would be safe from molecular/bacterial contamination. This study implemented the procedure into a developed system for the alignment of PDMS stamp. After adjusting the position of PDMS stamps applied with fibronectin-binding-fluorescent dyes with three different colors, contact printing was performed. As a result, the error of position between two different patterns of fibronectin was within 33 μm. This method would be useful for generating a multi-type-cellular tissue in tissue engineering and regenerative medicine.