Design of a Robotic Arm System for Pipetting and Sample Handling in Drug Susceptibility Experiments with Mycobacterium Tuberculosis Bacteria

The increasing prevalence of multidrug-resistant tuberculosis (MDR- TB) has intensified the need for laboratory systems capable of handling Mycobacterium tuberculosis samples with high biosafety standards. This paper presents the design of a mechatronic system for automating drug susceptibility tests (DSTs) through the manipulation and pipetting of bacterial samples using a robotic arm. The system integrates a robotic arm mounted on a linear rail, a custom-designed gripper for sample tube and Petri dish handling, and an automated pipetting module. The entire process is enclosed within a Class II biosafety cabinet. 3D models of the mechanical components were developed and analyzed with a finite element analysis software to ensure structural integrity under operational loads. The control system, based on a PLC architecture, coordinates the interaction between subsystems and provides a user-friendly interface via an HMI. Preliminary simulations confirm the system's operational feasibility, indicating a significant reduction in biohazard risk and an increase in process repeatability. The proposed system offers an innovative approach to automate high-risk microbiological procedures in TB diagnostics.