Micro-conveying station for assembly of micro-components

This paper describes a micro-conveying station for micro-component assembly. It incorporates micro-grippers joined up a micro-conveyer stage. The micro-grippers are fabricated from a mechanical structure in polymer using micro-stereophotolithography process and actuated by shape memory alloy wires. The micro-grippers can work in a space of 10 mm diameter and can carry out opening and closing movements. Neural network identification and PID control are proposed for the closed-loop control the micro-grippers, and trajectory control is realized on one finger. The micro-conveyer stage uses surface acoustic waves generated from interdigital transducers to move a slider onto the surface of the substrate with a high degree of resolution (nanometer) and in several centimetres of operation length. A mechanical model for the energy transfer from the acoustic wave to the slider is proposed. A good agreement between the theory and the experiment is obtained.