Sefati et al., PNAS (2013)

Mutually opposing forces during locomotion can eliminate the tradeoff between maneuverability and stability

Proceedings of the National Academy of Sciences (PNAS) ARTICLE #201309300

Shahin Sefati, Izaak D. Neveln, Eatai Roth, Terence R. T. Mitchell, James B. Snyder, Malcolm A. MacIver, Eric S. Fortune, Noah J. Cowan*

*Corresponding author (410-516-5301; [email protected])

Videos and images:

Biological experiments are integrated with a computational model and experiments with a biomimetic robot.

Photo Credit: Will Kirk.

Experimental apparatus.


    For small maneuvers, counter-propagating waves requires significantly less control effort than is required for a single traveling wave. We programmed a biomimetic robot to move forward and backward using both strategies. As shown, the relative control effort for a single traveling wave, when compared to counter-propagating waves, goes to infinity as the forward-backward motion amplitude decreases to zero.

Experts in the field not involved in this study:

JHU press release:
“Scientists Study Some Fishy Behavior to Solve an Animal Locomotion Mystery”

Lead author:
Shahin Sefati
Department of Mechanical Engineering
Johns Hopkins University
Baltimore, MD 21218
Telephone: 410-982-9616
e-mail: [email protected]

Corresponding Author:
Noah J. Cowan
Department of Mechanical Engineering
Johns Hopkins University
3400 N. Charles Street, Baltimore, MD 21218, USA
Telephone: 410-516-5301
Fax: 410-516-4316
e-mail: [email protected]

Principle Investigators from Collaborating Universities:
Eric S. Fortune
Department of Biological Sciences
New Jersey Institute of Technology
Newark, NJ 07102-1982 USA
Telephone: 443-312-9610
Fax: 973-596-5689
e-mail: [email protected]

Malcolm A. MacIver
Department of Biomedical Engineering
Northwestern University
Evanston, IL 60208
Telephone: 847-491-3540
e-mail: [email protected]

Other videos from collaborating laboratories: