Uni-direction orienting and size effect automatic alignment using capillary based in fluidic self-assembly process

Recent advances of miniaturization and microfluidics lead to novel technologies in assembling micro-scale electronic components in thousands and in parallel. Present study proposes a fluidic self-assembly (FSA) approach for fast, economic, and precise handling of micro-scale parts in asymmetric shapes. The micro parts, fabricated from siliconoxide wafers and ranged in size from 350×350×170 μm² to 1000×1000×440 μm³, are aligned and filled to designated sites in the substrate under water using a pipette. The adhesion force of square-patterned micropart immobilized at the bigger binding sites was estimated at 117 ±15 μ N, resulting in highter assembly yield of up to 73% for these sample. Furthermore, the novel designs of two dimensional tear-drop/rocking-chair like shapes are employed to improve the recovery angle and reduce the energy barrier for micropart alignment in uni-direction. Filling ratio of 90% is achieved with uni-direction if five hundred parts are filled to all of 64 binding sites with the agitation by an orbital shaker. © 2007 IEEE.