Underwater exoskeletons mimic dolphins and penguins
September 26, 2008 The University of West Florida’s Institute of Human and Machine Cognition has released designs of biologically inspired aquatic exoskeletons – robotic suits that enhance the user’s strength and allow them to mimic the efficient swimming styles of penguins, dolphins and turtles. The exoskeletons will provide great advancements in the speed, stealth and maneuverability of frogmen, though admittedly “penguin-men” doesn’t present much of an improvement in the nickname department.
A slew of powered exoskeleton prototypes designed to enhance human strength and endurance have emerged over the past few years: Raytheon is working on models to increase the effectiveness of soldiers; Berkeley's Lower Extremity Exoskeleton helps users carry immense weights; and Cyberdyne’s extremely impressive HAL system assists people with disabilities (though the company and product names don't fill us with confidence).
The West Florida team predicts that their underwater exoskeleton design will allow swimmers to reach a cruising speed of 1 m/s, and a top speed of over 1.5 m/s, with 504-Watts power consumption. Currently, divers equipped with fins swim at approximately 0.5 m/s over an extended period of time.
The underwater exoskeleton concepts emulate two types of biological propulsion: body and/or caudal fin locomotion, where the undulation of the body moves it through water; and median and/or paired fin locomotion, where the manipulation of fins provides the thrust. For reference, BCF locomotion is used by dolphins, while MPF locomotion is used by penguins and turtles. Both categories are extremely efficient in the animal kingdom, but the former style is more familiar, and less ridiculous looking, when applied to humans, (the latter style of exoskeleton, which employs fin-flapping, was diplomatically described by the researchers as having “the advantage of novelty” and “appeal as a recreational device.”)
The dolphin-based exoskeleton augments the lower body in order to generate more powerful and efficient flipper strokes. The swimming motion of users remains unchanged in this design, resulting in an intuitive, responsive system. The researchers are also investigating whether increasing the force of the up stroke results in greater speed – if the theory bears out, the exoskeleton will further improve swimming efficiency.
The second exoskeleton design provides users with lift-based arm fins, based on the biology of turtles and penguins. While similar design elements have been successfully incorporated in underwater vessels, the researchers are not overly optimistic about its application on humans. Like the previous exoskeleton, this model would detect and amplify human movement, allowing users to powerfully flap around underwater.
The next phase of the research involves constructing prototypes. And as with all exoskeleton projects, if the University is short of volunteers to test it out, sign us up!