Automated indirect transport of biological cells with optical tweezers using planar gripper formations

Optical tweezers are used for manipulation of micron-sized dielectric beads and cells. Some biological cells are vulnerable to photo damage if subjected to laser-based direct manipulation. In such cases, precise manipulation of these cells can be accomplished by using gripper formations made up of silica beads, which are actuated by optical tweezers. Manual indirect manipulation of cells using grippers made of optically trapped beads is a time consuming process or sometimes just impossible. This paper presents an approach for automated micromanipulation using gripper formations and heuristic based path planning for collision-free transport of biological cells. The objective of the developed planner is to transport target cells to their respective goal positions in the minimum time. we evaluated the performance of different gripper formations in terms of gripper stability, speed of transport, and required laser power using experiments.