Selective arraying of complex particle patterns.

Procedures requiring precise and accurate positioning of particles and cells have impacted a broad range of research interests including molecular detection, self-assembly and tissue and cell engineering. These fields would be greatly aided by more advanced, yet straightforward, micro-object positioning methods that are precise, scalable, responsive and flexible. We have developed an arrayed, multilayer surface patterned microfluidic device which uses laminar convective flow to actively position particles into any desired, two-dimensional, predesigned pattern. Objects including 10 microm polystyrene particles and Saccharomycodes ludwigii cells are rapidly (approximately 2 s) loaded onto vacuum-actuated holes, allowing us to both generate anisotropic particles and culture S. ludwigii cells. The device was further modified to individually control two sets of holes, adding control of pattern composition. With rapid, precise and adaptable operation, multilayer microfluidic devices should greatly assist in research where precise object placement and proximity is necessary.