Automated Indirect Transport of Biological Cells 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 glass beads actuated by optical tweezers. Indirect manual manipulation of cells using optically held micro-beads is a time consuming process or sometimes just impossible. This paper reports an approach for automated micromanipulation using gripper formations and an A* based path planning for collision-free transport of biological cells. The objective of the heuristic planner is to transport the cell in minimum time. Using the designed experiments, we evaluated the performance of different gripper formations in terms of gripper stability, speed of transport, and required laser power.