~~ The Department of Mechanical and Industrial Engineering Presents

Dr. Mohammad Elahinia

Associate Professor of Mechanical Engineering, University of Toledo

Topic: Additively Manufacturing NiTi Shape Memory and Superelastic Devices: A New Paradigm for Biomimetic Control

Abstract: Nickel-Titanium (NiTi) shape memory alloys (SMAs) with near-equiatomic exhibit both a thermal shape memory and superelasticity. Both effects are based on a reversible martensitic phase transformation. This type of the effect primarily depends on the transformation temperatures, which can be adjusted through variation in the Ni-Ti ratio. Currently, NiTi is the most commonly used SMA due to its outstanding functional characteristics and high working capacity, which far exceeds other SMAs. Due to the unique thermo-mechanical characteristic of these alloys, fabricating them to complex geometries has remained nearly impossible. Using additive manufacturing we have been able to achieve geometries and functionalities that have never been realized before. This includes the possibility of creating engineered porosity for medical implants with biomimetic characteristics, super-lattice structures for impact attenuation in the aerospace industry, combined shape memory-superelastic behavior for actuation, and structures with built-in and tunable damping characteristics for mitigating chatter in machining. One of the main areas of application is in developing assistive devices. The ankle, for example, is known to have a nonlinear and time-varying stiffness behavior. Using this technology we have succeeded at mimicking the behavior of the ankle joint, in an assistive device, through multi-axial loading of 3D fabricated SMA elements.

Short Bio: Mohammad Elahinia is currently an Associate Professor of Mechanical, Industrial and Manufacturing Engineering (MIME). He serves as Director of the Dynamic and Smart Systems Laboratory at UT. Dr. Elahinia’s research interests are in developing dynamic models and designing control systems for smart and active materials. His current research is focused on biomedical application of shape memory alloys. He is the PI from UT for a Third Frontier Project “Nitinol Commercialization Accelerator.” This accelerator is a $10 million investment by the State of Ohio, the Cleveland Clinic, NASA Glenn Research Center, Norman Noble Inc., the University of Toledo, and Case Western Reserve University. At UT he has served as investigator on 26 funded projects with a total budget of more than $6 million. These projects are funded by NSF, EPA, US Army, US DOT, Ohio Department of Development, Ohio Board of Regents, and the UT. Dr. Elahinia is the recipient of several awards, including the 2010 ASME Adaptive Structures and Material Systems Gary Anderson Early Achievement Award, 2010 University of Toledo College of Engineering Faculty Excellence Award, Outstanding Young Faculty Research Award from University of Toledo in 2006 and Torgersen Graduate Research Excellence Award from Virginia Tech in 2004. Dr. Elahinia is an Associate Editor for Journal of Intelligent Material Systems and Structures and Journal of Shock and Vibration. He also serves as the chair of the ASME Adaptive Structures and Material Systems Branch of the Aerospace Division.

Website