Product: Robot: Locomotion
unmanned underwater unit   (+1)  [vote for, against]
True Fish Motion in Unmanned Underwater Unit

If you embedded permanent magnets in a silicone fish shape along both lateral lines near the surface, and added two rows of independently-controlled electromagnets along either side of the ‘spine,’ matched to the permanent magnets, would a small electric charge to a specific electromagnet cause a deformation in the silicone that could be translated to movement? If the effect is real, could progressive waves of impulses result in a true fish motion, not only a swashing of the tail, which is most common and only allows slow movement and which cannot reproduce the speed of the mackerel or dorado.

With a cast silicone body incorporating a permanently embedded battery, magnets, wires, and electromagnets, a waterproof seal is achieved between the body and the removeable head, where the brains and connections are. With voids cast in the silicone the bending of the body is made easier. A ‘spine’ stiffener is run down most of the length of the body.

Slow swimming with the tail swash can be done by using only the aft actuators, but the beauty of the idea is that extremely fast, true fish-like motion is possible, as well as the whole range of speeds a fish exhibits. With the spine stiffener to provide resistance, fast, programmed impulses are sent down the length of the spine alternately, flexing along the whole length progressively and allowing the kind of speed you see from the ‘wriggling’ motion that replaces the swash when speed is necessary. You can see a mahi-mahi ‘shrug’ from a slow swashing to almost a vibratory state as they pick up speed. You can’t see the flexing when the animal is at full speed; it is very energy efficient after the initial effort is expended to get to speed. At some point the entire length is flexing very quickly like a bow, back and forth almost rigidly with no tail motion and just enough energy to maintain speed. There is a reason fish muscles extend the length of the body; they are meant to flex over their entire length as well as swash around at slow speed. This is the difference between goldfish motion and mahi-mahi motion.

This idea has been rolling around my head and my studio for 15 years. Plenty of drawings but nothing you could throw against the wall. I am not an engineer or any kind of experimenter, but am assailed with ideas that rely on knowledge I don’t have now and will never have. My role seems to be “burr in the saddle” when it comes to instigating, but not actualizing these notions. Perfectly halfbaked, no?
-- minoradjustments, Dec 23 2023

Overlaps with other idea of yours? S_3aUFA_20Swimming_...ter_20Fish_20Analog
[a1, Dec 23 2023]

I thought of other ways to achieve this true fish motion, particularly artificial muscles that would run horizontally in sequences down the length of the body but I don’t think the response speed is sufficient at the power available. I used magnets to capitalize on the potential energy. Maybe current developments have overtaken my concept.
-- minoradjustments, Dec 23 2023

Paging Dr. [Fries] ...
-- pertinax, Dec 23 2023

Wouldn't mechanical linkages be more energy efficient and have faster response times?
-- pocmloc, Dec 23 2023

Yah. I’ve just been going over it again. I’ll delete the older one as it’s the root of redundancy.
-- minoradjustments, Dec 23 2023

random, halfbakery