Let's Make Robots!

Gastropods - A silly Idea ??

Just about every method of locomotion in the animal world has been mimicked in robotics. I've seen Fish, hexapods, ornithopters, octopods, synthetic trunks and tentacles, bipeds, even monopods, tripods, milipedes, frogs and snakes

Yet for reasons that I guess in the main are obvious, (but when did obvious inutility ever stop us !) One entire taxonomic group has been missed out of the "robots mimicking nature stakes", and not a minor one either!

Now as a paleaonotology buff I feel the need to highlight what is probably one of the oldest and certainly most successful forms of locomotion - The Gastropod ! (slugs, snails and their relatives - over 80,000 named species, second only to the insects ), this fine group of creaures surely should be represented cybernetically. Yet I've never heard of a robot gastropod ! - why has no-one tried the GASTROBOT !! - I feel a strong urge to right this wrong.

Does such a beast exist and I've missed it ? - A quick google seems to draw very few uninspiring examples and none from the Hobby world.... I feel a mission coming on!

I'd have to define gastropod movement as having the following parameters - maybe in this thread we could explore further criteria that would have to apply for a robotic slug or snail to be sufficiently "sluggy" (no really, I'd value your thoughts!)  :

1/ Broad single contact space with the ground in a single flexible planar contact (a "foot" as in a slug or snail)

2/ Natural gastropods move by linear muscular contractions similar to peristalsys- often facilitated by exuding mucus (definite extra points for mucus!). So rule out tracks or belts of some kind.

Given their limited visual ability and slow pace of operation, I think some kind of "line follower" should be in order. maybe sensing the conductivity of a pre-laid slime trail.

for more info http://en.wikipedia.org/wiki/Gastropod

My first thought (inspired by hospital peristaltic pumps) is for a foot that uses a single fixed stretchable sheet across the bottom of the 'bot above which rotating units produce the necessary peristaltic waves like this :

Slug Foot drive

I figure 2 side by side under the single sheet could provide a "skid steer effect" I could even introduce synthetic mucus through holes in the latex base !

First the worm drive now the slug drive !




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Here's a Lego based slug robot. Not exactly a single surface, but you do need to make some adaptations in the robot world. The creator of this robot said he was inspired by a slug-like robot built by NASA, but I couldn't find any links to that.

I've definitely seen a robot that move by rolling a continuous surface tube like a water wiggly toy.

There was another robot that moves kind of like the blob. Work has been done on locomtion with a flexible skin transforming between liquid-like and solid-like states. iRobot call this mechanism, 'jamming'.

In any case, any slug-like bot should watch out for this class of slug digesting robot!

Interesting options,


I'd have to say the lego toy doesn't appear very "sluggish" to me though the water wiggly idea's kind of novel. The "jamming" approach is very similar to the way certain Amoeba move (sol-gel-sol), So I'd have to think of that as an amoe-bot !

I have seen the slug digesting robot in my googling, but I've still to find a good peristaltic example. I'm sure someone has hit on the idea somewhere (thre's nothing new under the sun!). I did find several japanese micro-bots for use inside of the human body, but these operate more like worms than slugs.

Still, the lego slug does look amusing. !

Slug robots have been around for a long time.

There used to be a small online hobby group that made a bunch of them as part of a MIT college project.

However I can't seem to find them.....they must have taken the site down for some reason.


Its funny you mention this now, as I'm nearly finished making one of these myself.

Though I'm using a different concept for my leg / pad drive system, which I'll disclose when I post the robot in a few days.

ive wondered about this and the use of vibrator motors.
it seems like the locomotion in slugs is generated by varying traction,
whatever part moves forward makes slime to reduce traction, whereas
whatever part is pushing back does not.

i was thinking of doing a 'skating' bot with vibrator disk motors for feet,
i guess this would be fairly similar.

another way it might be done is with air pressure.
have the foot have tiny holes like on a table hockey machine, and blow air
or suck air trough them to increase/reduce traction.


I was going to finish my slug robot but have lost interest.

Here's what I built:

Here's a video:



It works by using one way bearings on the rollers which only allow it to move forward. I also had planned on bolting on a servo for it to bend in the middle for steering, and a Sharp ranger for simple object detection. But since I've lost interest it'll be taken apart.