Automatic extruding system based on a visual servoing controlled robotic manipulator for developing arbitrarily shaped scaffolds

Purpose Commercial bioprinting systems are typically characterized by high costs and limited adaptability, presenting a significant barrier for academic research. This study aims to introduce and empirically validate an integral prototyping methodology for developing a low-cost, accessible robotic bioprinters. The primary objective is to provide a holistic framework that integrates mechanical design, electronics and control systems, aimed at addressing key engineering challenges. This work also addresses the critical issue of maintaining high positional accuracy in a system with a variable payload mass. Design/methodology/approach Following the Integral Prototyping framework, a multi-link robotic manipulator bioprinter was developed through an iterative process that integrated mechanical, electronic and control subsystems. A direct-drive extruder was implemented to minimize material waste by embedding cartridges into the end-effector, a design choice that created the central challenge of a variable payload. This study develops a payload-agnostic visual servoing controller. The system’s adaptability and the controller’s performance were validated by testing with five biomaterials and two 50:50 composites with diverse viscosities (gelatin-based hydrogel, lipid-rich emulsion, ground pork, starch-based hydrogel and composites), confirming the framework’s control strategy and the overall adaptability to heterogeneous biomaterials. Findings Application of the Integral Prototyping methodology resulted in a robotic bioprinter capable of sustaining high positional accuracy despite variable payloads. The visual servoing controller improved the system’s precision, reducing average positional deviations for key joint angles (e.g. from 13.18% to 6.62% for q1 and from 6.74% to 4.08% for q2), demonstrating effective compensation for mass variability introduced by the direct-drive extruder. The control system interfaces with standardized G-code to ensure both accuracy and accessibility. This control robustness translated into accurate fabrication outcomes, with dimensional deviations below 2.0% and scaffold fidelity deviations between 2.0% and 3.3%. Scaffold integrity was partially constrained given the configuration of the extrusion module. Results confirm that the control system successfully decouples positional precision from payload variability. These outcomes validate Integral Prototyping as a framework that not only integrates design, electronics and software but also resolves emergent engineering challenges central to accessible bioprinting. Originality/value The primary contribution is a reproducible Integral Prototyping methodology for developing low-cost, adaptable robotic manufacturing bioprinting platform that remain robust under variable operating condition. This work contributes in uniting design, electronics and control into a single framework while providing a validated visual servoing solution to the long-standing robotics challenge of variable end-effector mass. Beyond the specific controller, this study establishes a generalizable blueprint for rapid prototyping and tissue engineering, demonstrating that cost and flexibility barriers in bioprinting can be addressed through integrative, methodology-driven development.