DEVELOPMENT OF AN AUTONOMOUS IN-SITU BIOPRINTING SYSTEM FOR SKIN

Abstract

In-situ bioprinting and skin tissue engineering are at a pivotal threshold, necessitating a leap forward to realize their transformative potential. This study explores the integration of computational models, autonomous robotics, and customized biomaterials as key enablers for successfully navigating the complex anatomical landscape of the human body in bioprinting applications. It introduces a novel in-situ bioprinting approach designed to precisely deposit biomaterials on unconventional targets/platforms.

Central to this study is the development of an interconnected system that integrates: (i) a geometric modeling procedure to generate a free-form/planar toolpath for printing on anatomical models, (ii) an autonomous tracking and control algorithm to respond to the motions of the printing platform, (iii) a composite hydrogel formulation optimized for the direct extrusion printing process.

Results demonstrated that the slicing algorithm enhanced bioprinting adaptability and accuracy on free-form surfaces. Two slicing methodologies are proposed to model multi-layered heterogeneous skin implants: top-down and bottom-up approaches. Both leverage the implant interface's surface geometry, mitigating the staircase effect and providing control over interlayer interactions.

The developed asynchronous adaptive tracking and printer control system sustained print quality on substrates moving at speeds up to 50 mm/min while managing speeds up to 2500 mm/min. This marks the first instance of successful printing on moving platforms with real-time guidance of the in-situ printing process.

The optimized GelMA/CNF composite biomaterial exhibited enhanced mechanical and rheological properties, indicating its suitability for skin bioprinting applications. Characterizing GelMA's transition temperature sensitivity to heating and cooling rates facilitated its adaptation for the direct extrusion printing process.

This dissertation bridges hardware innovation and bioink development, offering a comprehensive approach to the challenges of in-situ bioprinting. This research lays the groundwork for future advancements in in-situ fabrication technology, paving the way for breakthroughs in bioprinting and the broader field of additive manufacturing.