Woodruff School of Mechanical Engineering

Faculty Candidate Seminar


Biologically-Inspired Lower Limb Exoskeletons


Dr. Gregory Sawicki


North Carolina State University


Thursday, September 15, 2016 at 11:00:00 AM


Engineered Biosystems Building, Room 1005


Aaron Young


Animals, including humans, can utilize elastic mechanisms to enhance muscle performance during locomotion. I will present some of our work highlighting how, at distal limb joints such as the ankle, long, compliant series tendon and aponeurosis can decouple joint and muscle displacements -- allowing muscles to operate at lengths and velocities that are favorable for economical force production, (i.e., during steady movements like constant speed running) or high power outputs (i.e., during accelerative movements like maximum distance jumps). Then, I will describe how we translated our understanding of elastic mechanisms to build a passive elastic exoskeleton and novel clutching mechanism that can provide ‘a spring in your step’ by storage and release of elastic energy in a parallel elastic element worn about the ankle (i.e., an exo-tendon) during human walking. We recently demonstrated that this device can reduce the metabolic cost of normal walking by ~7% below normal without adding any external energy from batteries or motors. We contend that simple, bio-inspired designs promise more functional assistive technology than current passive AFO product lines; and could provide a cheaper, more practical alternative to fully powered lower-limb exoskeletons now coming to market. Finally, I will briefly touch on a couple of current projects including: (1) a laboratory-based robotic testbed for high throughput parameter studies to evaluate physiology-based controllers for powered lower-limb exoskeletons and prostheses (2) development of a novel benchtop bio-robotic interface to explore the fundamental rules of optimal neuromechanical interaction in hybrid bio-robotic systems.


Dr. Gregory S. Sawicki is an Associate Professor in the Joint Department of Biomedical Engineering at North Carolina State University and the University of North Carolina at Chapel Hill. He holds B.S. (’99) and M.S. (’01) degrees in Mechanical Engineering from Cornell University and the University of California-Davis, respectively. Dr. Sawicki completed his Ph.D. in Human Neuromechanics at the University of Michigan, Ann-Arbor (‘07) and was an NIH-funded Post-Doctoral Fellow in Integrative Biology at Brown University (‘07-‘09). Dr. Sawicki joined the faculty at NC State in summer 2009. Dr. Sawicki directs the Human Physiology of Wearable Robotics (PoWeR) laboratory—where the goal is to combine tools from engineering, physiology and neuroscience to discover neuromechanical principles underpinning optimal locomotion performance and apply them to develop lower-limb robotic devices capable of improving both healthy and impaired human locomotion (e.g., for elite athletes, aging baby-boomers, post-stroke community ambulators). By focusing on the human side of the human-machine interface, Sawicki and his group have begun to create a roadmap for the design of lower-limb robotic exoskeletons that are truly symbiotic---that is, wearable devices that work seamlessly in concert with the underlying physiological systems to facilitate the emergence of augmented human locomotion performance.


Refreshments will be served.