ABSTRACT

Two photon polymerization is an additive manufacturing approach that relies on the use of ultrashort laser pulses to selectively polymerize photosensitive materials. The quadratic character of the two photon absorption probability and the well-defined polymerization threshold of this approach allow one to overcome the diffraction limit and obtain structures containing features below one micrometer. Two photon polymerization has recently been to create several classes of microstructured and nanostructured medical devices from biocompatible inorganic-organic hybrid materials (e.g., zirconium oxide hybrid materials) and polymers for medical applications. The use of biocompatible photoinitiators (e.g., a combination of riboflavin and triethanolamine) for two photon polymerization will be considered. The integration of electrochemical sensors with two photon polymerization-processed devices will be described. Evaluation of two photon polymerization- processed materials using in vitro and in vivo biological studies will be considered. In addition, application-specific studies  of two photon polymerization-processed medical devices for biosensing, drug delivery, and tissue engineering will be discussed. Our results indicate that two photon polymerization provides unique benefits for processing medical devices with small-scale features and unique medical functionalities.

BIOGRAPHY

Dr. Roger Narayan is a Professor in the Joint Department of Biomedical Engineering at the University of North Carolina  and North Carolina State University. He is an author of over two hundred publications as well as several book chapters on processing of biomedical materials. He currently serves as an editorial board member for several academic journals, including as associate editor of Applied Physics Reviews (AIP Publishing). Dr. Narayan has also edited several books, including the textbook Biomedical Materials, Second Edition (Springer), the handbook Materials for Medical Devices  (ASM International), and the Encyclopedia of Biomedical Engineering (Elsevier). He has previously served as director of  the TMS Functional Materials Division and the ASM International Emerging Technologies Awareness Committee; he currently serves as chair of the American Ceramic Society Bioceramics Division. As the 2016-7 ASME Swanson Fellow, Dr. Narayan worked with America Makes, the US national additive manufacturing institute, on several activities to disseminate additive manufacturing technology, including the development of an workforce, education, and outreach roadmap for additive manufacturing, and the development of a repository containing educational materials related to additive manufacturing. Dr. Narayan has received several honors for his research activities, including the NCSU Alcoa Foundation Engineering Research Achievement Award, the University of North Carolina Jefferson-Pilot Fellowship in Academic Medicine, the National Science Faculty Early Career Development Award, the Office of Naval  Research  Young Investigator Award, and the American Ceramic Society Richard M. Fulrath Award. He has been elected as Fellow of AAAS, ASM International, AIMBE, and American Ceramic Society.