This study aims to provide a set of experimentally determined forces needed for gripping operations related to a robotically manipulated microliter manual pipette. The experiments are conducted within the scope of automated sample processing for polymerase chain reaction (PCR) analysis in small-sized to medium-sized laboratories where dedicated automated equipment is absent and where procedures are carried out manually. Automation is justified by the requirement for increased efficiency and to eliminate possible errors generated by lab technicians. The test system comprises an industrial robot; a dedicated custom gripper assembly necessary for the pipette; pipetting tips; and mechanical holders for tubes with chemical substances and genetic material. The selected approach is to measure forces using the robot’s built-in force–torque sensor while controlling and limiting the pipette’s gripping force and the robot’s pushing force. Because the manipulation of different materials requires the attachment and discarding of tips to and from the pipette, the operator’s perceived tip release force is also considered.
This study provides a set of designs, simulations and experiments for developing an actuating method for manual pipettes. The goal is to enable robotic manipulation and automatic pipetting, while using manual pipetting devices. This automation is designed to be used as a flexible alternative tool in small and medium-sized biochemistry laboratories that do not possess proper automated pipetting technology, in order to relieve the lab technicians from the tedious, repetitive and error-prone process of manual pipetting needed for the preparation of biological samples. The selected approach is to use a set of pressure-controlled pneumatic cylinders in order to control the actuation and force of the pipettes’ manual buttons. This paper presents a mechanical design, analysis, pneumatic simulation and functional robotic simulation of the developed device, and a comparison of possible pneumatic solutions is presented to explain the selected actuation method. Remote pneumatic pressure sensing is employed in order to avoid electrical sensors, connectors and wires in the area of the actuators, thus expanding the possibility of working in some electromagnetic-compatible environments and to simplify the connecting and cleaning process of the entire device. A functional simulation is conducted using a combination of software packages: Fluidsim for pneumatic simulation, URSim for robot programming and CoppeliaSim for application integration and visualization. Experimental validation is conducted using off-the-shelf pneumatic components, assembled with 3D-printed parts and mounted onto an existing pneumatic gripper. This complete assembly is attached to an industrial collaborative robot, as an end effector, and a program is written to test and validate the functions of the complete device. The in-process actuators’ working pressure is recorded and analyzed to determine the suitability of the proposed method and pipetting ability. Supplemental digital data are provided in the form of pneumatic circuit diagrams, a robot program, simulation scene and recorded values, to facilitate experimental replication and further development.