On-chip fabrication and manipulation of hybrid-microstructure for improving manipulation performance

The microstructures are expected to be used as the components of on-chip single cell analysis system such as cell manipulation and measurement tools. We previously proposed a method to fabricate and assemble the microstructures within a microfluidic channel. Micro objects with arbitrary shape are fabricated by illumination of patterned UV-ray through the mask. The arbitrary shape objects are made of the photo-crosslinkable resin on the microfluidic device under a microscope and these objects are manipulated by optical tweezers. In this paper, we report a method of hybrid-microstructures fabrication which improves the trapping efficiency by optical tweezers. The hybrid-microstructure is composed of the photo-crosslinkable resin and polystyrene beads. The manipulation speed of the hybrid-microstructure increases when the optical tweezers trap the polystyrene beads. This is because the trapping efficiency of spherical configuration is higher than that of planar shape. We fabricate this hybrid-microstructure and evaluate the trapping efficiency compared with normal microstructure.