Robotic Stirring Mechanism with Novel Actuator for an Automated Drug Discovery Workcell

The pharmaceutical market has been growing rapidly, but concerns about energy and resource sustainability have made it important to consider the economical and sustainable aspects of discovering functional molecules in synthetic chemistry. One of the main challenges of traditional chemical synthesis is that it is labor-intensive and generates a lot of waste due to repetitive reaction manipulation. To address this issue, this paper presents a robotic end effector system with three degrees of freedom (DOF) to facilitate the automation of tasks in a drug discovery workcell. This robotics system features a unique remote center of motion (RCM) spherical-linear mechanism and a novel hollow double spring vacuum actuator (HDSVA) that uses soft elastic material and springs for actuation and structural integrity. This paper covers the design, kinematics, and actuation of the system. The HDSVA is modeled analytically and the interaction between the spring and soft membrane is examined. Through kinematic analysis, simulation results, and experimental evaluations, we examine the motion capabilities and validate the feasibility of this robotic end effector system in automated stirring tasks.