Tuning Injectability and Mechanical‑Processing Behavior of Biomedical Materials for Additive Manufacturing

As one of the pivotal material characteristics for additive manufacturing of biomedical implants and devices, particularly those deployed in extrusion-type and direct-writing processes, injectability fundamentally dictates the feasibility of printing workflow, and delivers critical underpinning for the quality, dimensional precision and industrial implementation of the final as-built component. It is collectively governed by series of material physicochemical properties and injection conditions (such as viscosity, solid-liquid ratio and injection volume, etc). It is known that the shear-thinning behavior of injectable materials plays a critical role in direct-write additive manufacturing. However, in this study, experimental results demonstrate that the elastic compressibility of particle suspension system exhibits the prominent influencing on slurry injectability. As the result, tuning the elastic compressibility of materials via a minimal dosage of additives holds great promise to effectively boost the injectability of additive manufacturing material. Meanwhile, the optimized mechanical-processing behavior also exerts a pronounced influence on a wide range of printing properties including injectability of solid-liquid composite. The proper mechanical processing of biomaterials can significantly enhance the clinical outcomes of additively manufactured medical devices.

Dr. Lei Yang is currently the university professor at the University of Health and Rehabilitation Sciences, China. He received Ph.D. in Engineering and M.S. in Innovation Management and Entrepreneurship from Brown University (USA), and both M.E. and B.E. in Materials Science and Engineering from Tsinghua University (PR China). His research interests focus on novel biomaterials and medical devices for orthopedic applications. He has authored 3 books, and over 100 publications in high-profile journals including Nature Biomed Eng, Mater Today, Spine J and J Orthop Translat. His work has generated more than 20 authorized Chinese patents and 2 US patents. He serves as the Associated Editors of Int J Nanomed and J Mater Sci & Tech. He is also the recipients of the Royal Academy of Engineering (UK) LIF Fellowship, International Society of Orthopaedic Surgery and Traumatology (SICOT) Research Award, and the Outstanding Young Scholar (2020) and Excellent Young Scholar (2016) Programs from the National Natural Science Foundation China.