I started to wonder about the possibility of a tentacle massage machine. To make the setting even more bizarre, it was intended to be a mass market home appliance. The tech level should be comparable to contemporary, with somewhat better electronics and data processing.

The thing that makes me wonder: is there on this tech level any practical way of inexpensively (and safely) designing such flexible tentacles? Inflatable? Some hydraulics?

EDIT (clarification): I mostly though about tentacles in style of gigant octopus. Assuming however, that someone thinks that this size is unfeasible, unpractical or too expensive for mass market then solution for mind flayer or tiny squid are also fine.

EDIT 2: People who think its an offtopic please clarify your reasoning. The setting is intended to be original but disturbing on many levels (not a planet of hats), while still NOT being a hard line dystopia. How should I ask questions for that?

EDIT 3: I mean a machine that massages human beings by using some kind of mechanical tentacles.

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    $\begingroup$ I've seen enough to know where this is going... $\endgroup$
    – Secespitus
    May 23, 2017 at 13:10
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    $\begingroup$ Can you say more about the tentacles? I imagine the approach would be different for a giant octopus, a mind flayer, and a tiny squid. $\endgroup$ May 23, 2017 at 13:13
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    $\begingroup$ Technically this isn't really off topic...use downvotes if you don't like a question. $\endgroup$
    – James
    May 23, 2017 at 14:09
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    $\begingroup$ Are we talking about a massage machine that has tentacles, or a machine for massaging tentacles? Because squid need massages too, after all... $\endgroup$
    – Werrf
    May 23, 2017 at 14:35
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    $\begingroup$ @Theraot I'd have never deduced that... :) Anyway, such skills can be easily (for a roboticist who consults a physiologist) programmed into a computer. In addition to the tentacles (@sphenning's "soft robotics" sounds interesting), you'd have a pressure-sensitive mat to determine how large the person is, and a thermal sensor to determine which muscles are tense. $\endgroup$
    – RonJohn
    May 23, 2017 at 15:56

3 Answers 3


This totally depends on what kind of massage you're thinking of. Most deep massages require a considerable amount of pressure - some masseuses will use their elbows or even heels. To achieve that - and, by the way, such a machine will be able to exert dangerous amounts of pressure - you're going to need hydraulics.

Soft or "finger" massages can use memory-form metals, pneumatics (here, for grips), or coil-and-wire setups (also called "spider motion" because this is how most arachnids' legs work; they're naturally bent, and the critter has to strain to distend them; the opposite of how human limbs work).

Then you have an additional form of massage which is not really feasible for humans: a tentacle can extert a considerable striction or compressive force, which may turn useful as a sort of lymphatic drainage massage on steroids.

However powered, your tentacles would probably end up being composed of a series of short, rigid sections with one, possibly two degrees of freedom each, one to "flex/bend" and one to (slightly) rotate. The last two or three sections on the tip could also be equipped with a piston (i.e. the tentacle tip can stretch forward), adding a third degree of freedom.

One thing the massaging tentacles would surely need is a biocompatible, sturdy silicon skin. Optionally they might need heating for comfort, and for special purposes the capability of delivering electrical currents. Support for vibration could also be a plus.

The tentacles would require some way of analyzing the part being massaged (if only to be sure they're not accidentally kneading your carotid sinus). The best way would probably be via ultrasound (as @AndyD273 observed, this would recommend coating the imaging tentacles with ultrasound gel, i.e. slime. That might be a plus or a minus depending on the scenario).

For approaching the part, some kind of camera would be needed. The capability of such a camera to "see" into the infrared could also turn out to be useful as it would allow to estimate blood flow.

In case someone wanted to implement specially purposed tentacles (the scientific term would be hectocotyli) little would need to be done except modifying the controlling software; there could even be a black market of creative mods.

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    $\begingroup$ Another benefit of equipping your tentacles with ultrasound is that ultrasound can be used for deep tissue massage, which could lessen the amount of pneumatics needed. The tentacles would need to be coated in gel to facilitate the transmission of the ultrasound waves. en.wikipedia.org/wiki/Therapeutic_ultrasound $\endgroup$
    – AndyD273
    May 23, 2017 at 16:58
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    $\begingroup$ @AndyD273 So effectively the tentacles should look like in an Alien movie because of being covered with mucus? Thanks, that clearly improves this setting. :D $\endgroup$
    – Shadow1024
    May 25, 2017 at 12:11
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    $\begingroup$ @Shadow1024 Exactly! But more importantly, it's functional, and not just because tentacles really should be slimy... ;) $\endgroup$
    – AndyD273
    May 25, 2017 at 13:02

I'd look into soft robotics. This is a branch of robotics without hard components like motors or rigid structure. Tentacle like appendages are a common project among engineers working on the technology.

Most of the work being done now involves a soft latex form with multiple voids inside of it. Changing the pressure differential between voids will inflate some and contract others leading to a bending motion.

  • $\begingroup$ My thought exactly! $\endgroup$
    – JDługosz
    May 23, 2017 at 18:58
  • $\begingroup$ Thanks for suggesting in to looking in to soft robotics, if I could I'd accept also this answer. $\endgroup$
    – Shadow1024
    May 30, 2017 at 13:02

Since you're going for bizarre, here's an idea:

Imagine a reclining chair with a fluid-filled sac attached to the back. This sac contains either bio-harvested octopus appendages or an actual Octopus which is preserved in a formaldehyde-like liquid.

An electric current is applied to the Octopus/appendages to make the tentacles move about in a rhythmic fashion. The person sitting on the chair feels this through the seat.

You can add minor details about how the tentacles are held upright and outstretched via attachments so that the entire assembly doesn't move around and out of position. The bag can either be solid black, transparent, or semi-transparent which shows the animal inside.

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    $\begingroup$ You promised bizarre, and bizarre is what you suggested... I have some doubt wether or not this should be considered an answer, but since i like it, have a +1 :-) $\endgroup$
    – Burki
    May 24, 2017 at 8:02
  • $\begingroup$ Maybe you could have octopus arms grown from stem cells, and then control them with implanted electric wires... $\endgroup$ May 14, 2022 at 16:55

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