Google Science Fair Finalist Explains Squid-inspired Underwater Propulsion


Meet [Alex Spiride]. He’s one of the fifteen finalists of the 2013 Google Science Fair. A native of Plano, Texas, [Alex] entered his squid-inspired underwater propulsion system in the 13-14 year old category.

The red cylinder shown in the image inlay is his test rig. It is covered well on his project site linked above. You just need to click around the different pages using the navigation tiles in the upper right to get the whole picture. The propulsion module uses water sprayed out the nozzle to push the enclosure forward. The hull is made of PVC, with a bladder inside which is connected to the nozzle. The bladder is full of water, but the cavity between it and the hull is full of air. Notice the plastic hose which is used to inject pressurized air, squeezing the bladder to propel the water out the nozzle. Pretty neat huh?

We think [Alex’s] work stands on its own. But we can’t help thinking what the next iteration could look like. We wonder what would happen if you wrapped that bladder in muscle wire? Would it be strong enough to squeeze the bladder?

You can see all fifteen finalists at the GSF announcement page. Just don’t be surprised if you see some of those other projects on our front page in the coming days.

15 thoughts on “Google Science Fair Finalist Explains Squid-inspired Underwater Propulsion

  1. Hey on the subject of Google science fair entrants, I take it you’ve seen the peltier powered torch?

    Neat idea, from what she said and what we can see of the torch she attached 2 peltier devices to some aluminum tube, connected the peltiers to LEDs through a voltage boost cirucit, then covered the tube with a plastic tube to insulate it from the heat of your hands whilst having the peltiers open for your hand to heat up.
    She might want to add an endcap to it, putting cold water inside should work even better than plain air cooling of the aluminium tube.

      1. It’s not that bright, but it’s a science fair project. It’s principle.

        Reading the comments on that site, you’d think the girl just saved the world, or invented something totally new. One mentioned using heat to power cars! Um… they had steam powered cars years ago.

        It would probably work better if she added a super capacitor to store the energy while it’s just sitting there with the LED’s off.

      2. Sure in it’s present form you’re not going to be able to traverse through a forest at night but I see it as an interesting step towards a better designed human heat powered light source.

        I’m sure there’s someone out there who has seen (or will see) the torch and will try to create a more efficient version, and I want to see that when it happens, and possibly make one myself.

        1. Probably not, peltier junctions are notoriously inefficient. And using them as a power source is nothing new. What this girl did is not ground breaking or innovative.

  2. While cool that a he is young, and participating in a science fair. I will note that the efficiency of this operation is rigged. Air is lighter than water and is being pumped in by an outside source to move upwards. If up is the direction you want to measure with this, it is essentially flawed if used a a ballast (because you have to bring the same amount of air down with you). Also the side to side motions would change the lift of the machine. This needs either water as a displacement medium or some other way of actuating the water bag.

    1. how about a hydraulic cylinder on a crank shaft? you could use veggie oil as the hydraulic fluid to prevent damage to the ecosystem and could vary the speed of the motor to change the pulse rate.

    1. I just had the same idea. I just also realized that for submerged robots or subs this propulsion should be more quiet than the screw. Can you imagine military subs with mechanically actuated sacs?

      1. “mechanically actuated sacs”, LOL! Anyway one of the biggest problems with subs is cavitation from the propellers, if it starts everyone and his brother can hear you, and it at higher speeds its more likely, this squid propulsion would seem to avoid this problem.

      2. You don’t really need a sack per se, you can just use a standard peristaltic pump. That said, if you are pumping at high speeds, you will still have cavitation issues at the entrance and exit of the flow.

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