Here is an artificial muscle robot hand that could eventually be used as a prosthetic replacement for a human hand. The "bones" are 3d printed in PLA and the silicone rubber artificial muscles and skin were cast in 3d printed molds.

While most makers are not likely to want do duplicate this hand, some of the techniques used here might be found to be useful for other kinds of robots and casting.

Intro pic shows the hand holding a raspberry.

At this point, the soft robot fingers are a bit wobbly. I am working on adding an arm that will have room for more hand muscles. They would use tendons to open the fingers and balance the grasping muscles. This should stabilize the fingers and give a more natural movement.

The short video shows some of the movements of the robot hand.

Step 1: How It Works

This is an air powered hand that uses silicone artificial muscles as actuators. They are powered by compressed air. This gives it a soft touch that is much more human friendly than most robot hands. The artificial muscles are also very inexpensive to produce compared to traditional gear motors and servos.

Ideally, the whole thing would be printed completely in a 3d printer that printed a hard plastic and a soft rubber that holds air pressure. Since I have no access to such a machine, the soft silicone parts had to be cast in 3d printed molds.

This is an open source project. Version 1.0 is mainly a proof of concept--prototype and there is lots of room for improvements. While not near as strong as a human hand, it is strong enough to hold a cup of coffee or carry a briefcase.
<p>Nice Job !</p><p>Our Muscles can only pull and can't push so for each degree of freedom we have, we have a pair of muscles (called skeletal muscles) that alternate pulling in opposite directions. Apparently your system can only push, if you can implement two muscles for every DOF in your system, it'll be more than great additionally you'll have more accurate positioning.</p>
<p>i had the same idea about using a foot pump, but the guy i'm building this for thought it was too awkward.</p>
<p>i found a much more elegant solution to this problem. i'm not finished yet, but i'll post as soon as i get done. have really bad problems with moving my house right now.</p>
<p>i had the same problem with the molds. breakaway is a great idea.</p>
<p>this is very similar to a design i am building.</p>
<p>Thank you for you instructables, your works really inspire me !</p><p>I made my own research and find that carvable wax (this kind : <a href="http://www.freemanwax.com/pdfs/sol-u-carv.pdf" rel="nofollow">http://www.freemanwax.com/pdfs/sol-u-carv.pdf </a> ) can be used to make a soluble core. You can easy pour it in an silicon mold, then dissovle it in water.<br>Enjoy !</p>
<p>Great Instructable, your explanations and pictures are highly commendable. This is Instructables up a notch. Nice work!</p>
<p>Nice!</p><p>However,</p><p>1) there are no muscles in fingers nor thumb, all the muscles are located on the palm, back of the hand and, mainly, in the forearm.</p><p>2) hydraulic (air) is slow, weak and not so precise, oil would probably be a better choice. Electro-magnetic muscles would be more accurate and even more powerful, slicing plates of electro-magnets between rubber and alternating polarity would make it a lot more realistic, powerful (your limit is when you start getting arcs between the plates, they tend to burn the rubber) -- and fast. If your goal is to make a prosthetic hand, you probably want to match your set of muscles with the (existing) set of nerves (you'll probably need a little more inputs and outputs than what can be found on an Arduino, though)</p>
<p>Very cool - so what is powering the air?? I saw the other gripper but I wonder about calling it a robot as to me that implies that there are sensors for inputs and some kind of automated output (inflation here). How do you do that automation part? Thanks!</p>
<p>ah - I'd missed some of the later pages - I see now!</p>
<p>Wouah :D It's awesome, but just imagine this project with myo :</p><p>https://www.thalmic.com/en/myo/</p>
<p>That's so incredible! :D Love your concept of air muscles!</p><p>I'm a little bit surprised - this project should gain at least 100 times more views... Great work anyway!</p>
<p>This may be the best ible I have ever seen. Something I would expect to see come from an MIT student's senior design.</p>
<p>Great work ! besides the cool design it appears to me very well engineered with so many muscles fitting in a compact hand. Many compliments. I am always looking forward to your cool projects. </p>
<p>Awesome work! I'm a big fan of all your projects, especially the artificial/air powered muscles. Too cool. </p>
<p>Beautiful work. The movement on the fingers seems natural</p>

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Bio: I believe that the purpose of life is to learn how to do our best and not give in to the weaker way.
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