Knifefish are highly maneuverable swimmers capable of navigating
complex environments. The fish generate thrust by undulating an elongated ventral fin. We study the fin
mechanics using motion capture of live fish, computational fluid dynamics, and bio-inspired robotics.
Using these tools, we are uncovering the underlying principles of knifefish locomotion which can then
be implemented into underwater robotics to enhance maneuverability.
Below is a video that demonstrates the forward and backward traveling waves
along the ribbon fin of the black ghost electric knifefish.
We've built one of the most advanced fish robots in the world, with 34 degrees of freedom (the humanoid robot ASIMO has 26; the Roomba floor vacuum robot has 2), in order to better understand knifefish mechanics and sensorimotor coupling. This video is the first where we discovered that inward counter-propagating waves generate a strong downward jet, producing vertical thrust. This is a key element of knifefish maneuverability. The water is seeded with reflective particles for subsequent particle imaging velocimetry.
In this video, Ghostbot demonstrates 'nodal point control' in which a closed-loop positioning algorithm shifts the point at which inward counter-propagating waves meet in order to control position.
We perform 3D Navier-Stokes simulations of fish and robot locomotion. Shown here is forward swimming followed by a rapid reversal, similar to what we discovered the real fish uses for hunting prey.
Sense organ control in moths to moles is a gamble on information through motion
Chen Chen, Todd. D. Murphey, Malcolm A. MacIver
Under revision, eLife, 2020 (Preprint,
Video Explainer)
Feedback Synthesis For Underactuated Systems Using Sequential Second-Order Needle Variations
Giorgos Mamakoukas, Malcolm A. MacIver, Todd D. Murphey
The International Journal of Robotics Research, 2018 (Article)
Superlinear Convergence Using Controls Based on Second-Order Needle Variations
Giorgos Mamakoukas, Malcolm A. MacIver, Todd D. Murphey
IEEE Conference on Decision and Control, Miami Beach FL, 2018 (Article)
Feedback Synthesis for Controllable Underactuated Systems using Sequential Second Order Actions
Giorgos Mamakoukas, Malcolm A. MacIver, Todd D. Murphey
Robotics Science and Systems, 2017 (Article, Video)
Ergodic Exploration of Distributed Information
Lauren M. Miller, Yonatan Silverman, Malcolm A. MacIver, Todd D. Murphey
IEEE Transactions on Robotics, 2016 (Article,
Video Explainer)
Sequential Action Control for Models of Underactuated Underwater Vehicles in a Planar Ideal Fluid
Giorgos Mamakoukas, Malcolm A. MacIver, Todd D. Murphey
American Control Conference (ACC), Boston MA, 2016 (Article)
Convergent evolution of mechanically optimal locomotion in aquatic invertebrates and vertebrates
Rahul Bale, Izaak D. Neveln, Amneet Pal Singh Bhalla, Malcolm A. MacIver, Neelesh A. Patankar
PLoS Biology, 2015 (Article)
Separability of drag and thrust in undulatory animals and machines
Rahul Bale, Anup A. Shirgaonkar, Izaak D. Neveln, Amneet Pal Singh Bhalla, Malcolm A. MacIver, Neelesh A. Patankar
Scientific Reports, 2014 (Article)
Separability of drag and thrust in undulatory animals and machines
Izaak D. Neveln, Rahul Bale, Amneet Pal Singh Bhalla, Oscar M. Curet, Neelesh A. Patankar, Malcolm A. MacIver
Journal of Experimental Biology, 2014 (Article)
Mutually opposing forces during locomotion can eliminate the tradeoff between maneuverability and stability
Shahin Sefat, Izaak D. Neveln, … , Malcolm A. MacIver, Eric S. Fortune, Noah J. Cowan
Proceedings of the National Academy of Sciences, 2013 (Article)
Biomimetic and bio-inspired robotics in electric fish research
Izaak D. Neveln, Yang Bai, … , Malcolm A. MacIver
Journal of Experimental Biology, 2013 (Article)
Kinematics of the ribbon fin in hovering and swimming of the electric ghost knifefish
Ricardo Ruiz-Torres, Oscar M. Curet, George V. Lauder, Malcolm A. MacIver
Journal of Experimental Biology, 2012 (Article)
Counter-Propagating Waves Enhance Maneuverability and Stability: A Bio-Inspired Strategy for Robotic Ribbon-Fin Propulsion
Shahin Sefati, Izaak D. Neveln, Malcolm A. MacIver, Eric Fortune, Noah J. Cowan
4th IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob), 2012 (Article)
Optimal number of waves for ribbon fin propulsion
Rahul Bale, Amneet Pal Singh Bhalla, Malcolm A. MacIver, Neelesh A. Patankar
Bulletin of the American Physical Society, 2012 (Article)
Mechanical properties of a bio-inspired robotic knifefish with an undulatory propulsor
Oscar M. Curet, Neelesh A. Patankar, George V. Lauder, Malcolm A. MacIver
Bioinspiration & Biomimetics, 2011 (Article)
Aquatic maneuvering with counter-propagating waves: a novel locomotive strategy
Oscar M. Curet, Neelesh A. Patankar, George V. Lauder, Malcolm A. MacIver
Journal of the Royal Society Interface, 2011 (Article)
Hydrodynamic optimality of ribbon fin shapes
Rahul Bale, Malcolm A. MacIver, Neelesh A. Patankar
Bulletin of the American Physical Society, 2011 (Article)
Can drag and thrust be separated in undulatory swimming
Neelesh A. Patankar, Anup A. Shirgaonkar, Malcolm A. MacIver
Bulletin of the American Physical Society, 2009 (Article)
Multi-directional thrusting using oppositely traveling waves in knifefish swimming
Oscar M. Curet, Malcolm A. MacIver, Neelesh A. Patankar
Bulletin of the American Physical Society, 2009 (Article)
The hydrodynamics of ribbon-fin propulsion during impulsive motion
Anup A. Shirgaonkar, Oscar M. Curet, Neelesh A. Patankar, Malcolm A. MacIver
Journal of Experimental Biology, 2008 (Article)
Hydrodynamic aspects of thrust generation in gymnotiform swimming
Anup A. Shirgaonkar, Oscar M. Curet, Neelesh A. Patankar, Malcolm A. MacIver
Bulletin of the American Physical Society, 2008 (Article)
An efficient algorithm for fully resolved simulation of freely swimming bodies
Anup A. Shirgaonkar, Neelesh A. Patankar, Malcolm A. MacIver
Bulletin of the American Physical Society, 2007 (Article)
Infomechanical specializations for prey capture in knifefish
Malcolm A. MacIver, Neelesh A. Patankar, Oscar M. Curet, Anup A. Shirgaonkar
Bulletin of the American Physical Society, 2007 (Article)
Simulation of bio-locomotion by a momentum redistribution technique for self-propulsion
Oscar M. Curet, Anup A. Shirgaonkar, Neelesh A. Patankar, Malcolm A. MacIver
Bulletin of the American Physical Society, 2007 (Article)
An algorithm for low to moderate Reynolds number swimming
Oscar M. Curet, Neelesh A. Patankar, Malcolm A. MacIver
Bulletin of the American Physical Society, 2007 (Article)
Hydrodynamics of ribbon fin-based swimming with application to highly maneuverable underwater vehicles
Neelesh A. Patankar, Oscar M. Curet, Malcolm A. MacIver
Bulletin of the American Physical Society, 2006 (Article)
Generating thrust with a biologically-inspired robotic ribbon fin
Michael Epstein, J. Edward Colgate, Malcolm A. MacIver
IEEE/RSJ International Conference on Intelligent Robots and Systems, 2006 (Article)
Towards direct numerical simulation of freely swimming fish
Oscar M. Curet, Neelesh A. Patankar, Malcolm A. MacIver
Bulletin of the American Physical Society, 2006 (Article)
A biologically inspired robotic ribbon fin
Michael Epstein, J. Edward Colgate, Malcolm A. MacIver
IEEE/RSJ International Conference on Intelligent Robots and Systems, workshop on Morphology, Control, and Passive Dynamics, 2006 (Article)
Designing future underwater vehicles: principles and mechanisms of the weakly electric fish
Malcolm A. MacIver, Ebraheem Fontaine, Joel W. Burdick
IEEE Journal of Oceanic Engineering, 2004 (Article)