Affordable Pipetting Robot: Gripper Design for Automatic Changing of Micropipette and Liquid Volume Control

Abstract

Laboratory automation provides a more reliable solution while potentially reduces human participation. Volume and dropping time are precisely controlled by liquid handling robots. This paper presents our built pipetting robot suitable for life sciences and pharmaceutical laboratories dealing with many liquids and micropipettes of different scale ranges. The SCARA manipulator having four degrees of freedom is capable to move the pipet’s microtip to any desired position and the gripper’s orientation can be maintained while the robot is grasping a micropipette from a hanger or returning it back. The compact robotic arm provides sufficient workspace for the number of test tubes and clean microtips. A Roh’Lix transmission is used for intrinsically safe vertical motion. The gripper and the pipetting stand are custom designed to allow automatic changing of commercial micropipettes. Instead of manually adjusting the rotary knob scale to set the pipetting volume, a micro linear actuator is applied to compress the pipetting button with precise displacement. The liquid volume varying against the displacement of the micro linear actuator was validated experimentally. A contaminated microtip is released by using another micro linear actuator before installing a new one.