Woodruff School of Mechanical Engineering

Mechanical Engineering Seminar


High Force Linear Electric Motors: Bioinspired Design for Biomedical Applications


Dr. Bryan Ruddy


University of Auckland, New Zealand


Tuesday, October 8, 2019 at 11:00:00 AM


MRDC Building, Room 4211


Ellen Mazumdar


Actuator performance remains the key limitation to the capabilities of robots and other machines that work around people; however, the actuators that power these machines are fundamentally similar to those in use 50 years ago, comprising rotary motors with gear reductions and fluidic actuators controlled by valves. In this presentation, we will discuss new design approaches to a different class of actuator, the linear electric motor, and exhibit several applications for these enhanced actuators to problems in medical devices and robotics. To overcome the traditional poor efficiency of linear electric motors, we will discuss bio-inspired co-optimization approaches based on the architecture of biological muscle that simultaneously maximize efficiency of force production and minimize thermal resistance, deeply integrating heat transfer into the design of small actuators. We will then discuss two applications of these high-force linear motors: a needle-free jet injection system, which generates controlled pulses of high fluid pressure to produce high-speed liquid jets capable of penetrating human skin, and a shoulder exoskeleton capable of providing flexible gravity support of the upper arm during rehabilitation, without obstructing natural motion. Finally, we will discuss future approaches to further leverage ideas from biological muscle architecture and achieve truly muscle-like performance from electromagnetic actuators.


Bryan P. Ruddy holds a joint appointment as a Research Fellow in the Auckland Bioengineering Institute and as a Lecturer with the Department of Engineering Science, both at the University of Auckland, New Zealand. Dr. Ruddy’s research focuses on model-based multiphysics design of electromagnetic actuators, and on applications of these actuators to medical devices for drug delivery, rehabilitation, and musculoskeletal diagnosis. He received his PhD in Mechanical Engineering from MIT in 2012.


Refreshments will be served.