Preface

ASM Handbook, Volume 23A, Additive Manufacturing in Biomedical Applications, considers the use of additive manufacturing and bioprinting technologies for medical applications. The volume follows the 2020 publication of ASM Handbook, Volume 24, Additive Manufacturing Processes and the 2012 publication of ASM Handbook, Volume 23, Materials for Medical Devices. These volumes, along with ASM Handbook, Volume 24A, Additive Manufacturing Design and Applications, which is in development, form a substantial knowledge base for those requiring the most up-to-date, peer-reviewed information on additive manufacturing and its subtopics.

Additive manufacturing has a relatively short history, but once launched, the development of its various technologies was quite rapid, and of course is still ongoing. Charles Hull filed a patent on the use of stereolithography to manufacture three-dimensional structures in 1984 ^[1]; in 1990, Mankovich et al. described the use of this approach to prepare surgical models ^[2]. Numerous applications of additive manufacturing for medical and dental products have been developed since that time. For example, Bespoke Fairings, a part of 3D Systems (co-founded by Charles Hull), uses additive manufacturing to create cover designs (known as fairings) for prosthetic limbs [³, ⁴]. Additive manufacturing of hearing aid shells was patented by Jan Topholm in 1992; by 2008, all six of the largest hearing aid manufacturers had adopted the use of additive manufacturing ^[5]. The use of additive manufacturing for dental applications, including the manufacturing of crowns, bridges, and implants, continues to grow ^[6]. Additive manufacturing of drugs has also been commercialized; for example, the epilepsy medication Spritam (levetiracetam) is manufactured by a technique called three-dimensional printing, which enables a large dose of the active ingredient to be loaded on a compact tablet ^[7]. In addition, the use of an approach called bioprinting, which involves including living cells or biologically active agents within the “bioink” that is processed using an additive manufacturing technology, is finding wider use. A bioprinted human full skin model called Poieskin®, which is made using a laser-assisted bioprinting approach, was commercialized in 2018 and is currently available as a tissue model for assessing cosmetic products ^[8].

Volume 23A considers both the additive manufacturing technologies that are used for medical applications and the various products in medicine and dentistry that make use of additive manufacturing technologies. It begins with introductory articles about methods, trends, and material aspects of additively manufactured medical devices; the next few divisions focus on polymer, ceramic, and metal additive manufacturing in biomedical applications. A division focuses on bioprinting, and the final division discusses various biomedical applications of additively manufactured materials.

I would like to acknowledge the tremendous efforts of the contributors and the ASM International staff, without whom this Volume would not be possible. I hope that this book serves as a resource for the growing medical additive manufacturing community as it continues to develop new materials, additive manufacturing processes, and commercialized products that enhance our quality of life.