Well, non-tethered artificial muscles are just artificial muscles that only need electric wiring in order to work; unlike pneumatic/hydraulic/vacuum actuators that need a external pump in order to contract.

I ask that because I want to build my own robot with soft robotics/artificial muscles.

However, all the equipment for pneumatics, vacuum and hydraulics are really expensive for robotics application (at least, where I live).

A single solenoid valve costing 88 euros for a single piston in an elevator is quite affordable, but 50 solenoid valves for 50 muscles? That would be... Really expensive.

I want to build a robot to interact with humans, and build it first and program it later, since I don't know anything about programming (probably not the best idea).

What I found until now:

  1. Mckibben muscles that have some kind of eletroclisis-like reaction inside them, releasing gases that expand the muscle:

    "Actuation of Untethered Pneumatic Artificial Muscles and Soft Robots": https://youtu.be/lOAr2nK2NLI

    But they need an external source of heat in order to work, even if it is made just with water and iron, the external material still can catch on fire.

  2. McKibben muscles that had some low boiling point fluid inside them (like ethanol) and an electric discharge boiled the liquid and the pressure made by the vapor expanded the muscle. But hey, who wants to mix ethanol with electricity with a machine made to interact with humans?

"New fully electric artificial muscle for prosthesis and robots - 1st version": https://youtu.be/89AmyJjYdzQ

  1. I also found dielectric artificial muscles, however, they need a LOT of energy to work, 10 kv just to contract is not the ideal to interact with humans.

"Realizing the potential of dielectric elastomer artificial muscles": https://youtu.be/LWDRlfruSBM

  1. Of course, there is also fishing line artificial muscles, but these need an specific type of nylon that are coated in silver (198 dollars a single coil and it just contracts 8% of its length).

  2. And, for the last one, this electromagnetic muscle that is just a bunch of electromagnets stacked together. These are easy to make and the ones I will more likely build, since It is really cheap and easy to make. But I don't know for sure if it will work in a robot the size of a human being, since electromagnets are heavy and not very powerfull unless you put kv of power.

“Electromagnetic Artificial Muscle 2020”: https://youtu.be/ZINr9ssGOvE

So? Do you guys know any artificial muscles that could be made/bought and are easy to use?

And yes, I know I could build if servos using elastic lines, but it would still not be soft enough to interact with human beings, just safe. Also, I asked on chemistry.stackexchange for opinions for chemical reactions, but they just downvoted me to hell and said I should just work with hydraulics.

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    $\begingroup$ the cheapest way to get started may be something like this ... imagesco.com/articles/airmuscle/AirMuscleDescription02.html ... you did say that you don't want an external compressor, but it may be an intermediate solution $\endgroup$
    – jsotola
    Jun 27 at 23:16
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    $\begingroup$ Welcome to Robotics Neto Ananias, but I'm afraid that shopping questions really aren't a good fit for a stack exchange site. We prefer practical, answerable questions based on actual problems that you face. Take a look at How to Ask and tour for more information on how stack exchange works, and the Robotics question checklist for details of how to write a good question. $\endgroup$
    – Chuck
    Jun 28 at 13:39
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    $\begingroup$ I feel like an artificial muscle without the pneumatic/hydraulic component is simply a linear actuator. Which is easily electro-mechanical. There are thousands of ways to achieve linear motion so I won't list them here. But one you should be aware of is the "electro-hydraulic actuator". $\endgroup$
    – Ben
    Jun 30 at 18:07
  • $\begingroup$ One option: Learn to make your own solenoid valves $\endgroup$
    – user253751
    Jul 5 at 16:52
  • $\begingroup$ @user253751 They need electric motors (like the solenoid valves on the market) and would cost the same price $\endgroup$ Jul 12 at 14:02