A pL-fL grade micro-dispensing by pipetting needle glue liquid transfer

Abstract

Nowadays, micro–nanomanufacturing technology and micro–nanodevices have seen some development, but many micro–nanodevices and microelectromechanical systems have not been practically used as products. This is because dispensing technology used in micro–nanosize encapsulation and assembly is one of the main obstacles, such as the size of the glue point, the amount of glue, and precision. In this paper, on the basis of the principle of transfer printing, an ultra-microautomatic dispenser method of pL-fL grade pipetting needle glue transfer type is proposed. This method involves controlling the pipetting needle pass through the capillary tube filled with glue liquid by the precision micro-displacement drive platform, making the terminal of the pipetting needle attach to a trace amount of adhesive, and then leaving a part of the glue liquid on the base plane to form tiny glue points using the adhesive force of glue liquid in contact with the base plane and the pulling force of the drive platform on glue liquid. The diameter of the glue point is about dozens of microns, and the amount of glue is pL of magnitude. In this paper, the dispensing process was simulated under different parameters, and the main factors affecting the dispensing process were preliminarily determined. The influence law of the diameter of the pipetting needle, movement speed, and residence time on the diameter of the glue point was analyzed by orthogonal experiment. On the basis of the influencing factors and laws obtained above, the automatic distribution of fL grade glue liquid was realized through a reasonable configuration of parameters. The minimum diameter of the glue point was 13.2 µm, and the volume was 26.3 fL.

Experiments and analysis for accurate controlling of an ultra-microvolume adhesive droplet in dispensing

“…In the gelation stage, the pipetting needle continues to move upward until the liquid bridge is broken. The adhesive left on the base spreads outward under the action of cohesion and viscous force until a transfer droplet is formed [13].…”