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Electro-Active Polymers. Any interest in this subject here?

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Dryden
(@dryden)
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By definition (Thanks to Wiki) 

Electroactive polymers, or EAPs, are polymers that exhibit a change in size or shape when stimulated by an electric field. The most common applications of this type of material are in actuators[1] and sensors.[2] [3] A typical characteristic property of an EAP is that they will undergo a large amount of deformation while sustaining large forces.

This is actually an old technology that you never really hear about, they are used in artificial heart valves and various other technologies. 

They are said to be very efficient and use very little energy, and in some applications actually generate electricity.

This is a Youtube playlist made up of 46, mostly short videos on the subject including university papers on the topic. 

 

I have been experimenting with making conductive silicone that is stretchy and flexible. 

Here is a bit of a tutorial I followed

With mixing 1 gram of chopped carbon-fiber (after being washed in alcohol)

with 10 grams of silicone diluted in mineral spirits. Mixed until it has a metallic sheen and the fibers are not as noticeable

I then poured the mixture onto a tray and smoothed it out the best I could and allowed it to set over night.

It produced a very acceptable result, it is a conductive rubber!

I have gone so far as to use it to light up an l.e.d.

Now I want to move toward building an actuator using this technology, namely along the lines of the H.A.S.E.L. actuators.

It really is the same concept as a capacitor, in fact this technology was originally discovered by the person that invented the capacitor, Charles Pollak in 1896, when he was experimenting in other materials to build capacitors.

In the application as an actuator, you can feed energy into this polymer capacitor and it can store that energy and hold a position without consuming more energy to hold that position, and then you can release that energy to release the actuator.

The energy used is high voltage but small current, its like static electric charges if I understand it correctly.

I need to figure out how to produce the right energy that these things need to operate, I believe I understand how to build these actuators, but I don't really understand the circuitry behind activating them.

Any thoughts or advise would be appreciated


   
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Dryden
(@dryden)
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I guess I should pay more attention to the play list I shared, the very first video shows them using an EMCO step up converter G50 to power the actuator.... 


   
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robotBuilder
(@robotbuilder)
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@dryden 

Instead of using a strong magnetic field produced by the flow of electrons in a coil of wire these are using a strong electric field produced by a very high static voltage source. Although perhaps fun to play with or as an area of research these "muscles" are interesting but from a practical point of view I don't see them as of any practical value yet.  Also for robots working in extreme environments you want them to be made out of strong materials not something that may melt or burn.

 


   
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Dryden
(@dryden)
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@robotbuilder 

Posted by: @robotbuilder

Also for robots working in extreme environments you want them to be made out of strong materials not something that may melt or burn.

Yes in extreme environments they probably wont be that great, but what about wearable robotics? or anything in an environment where it could be in contact with a person.

Got any ideas with using house hold materials to make  a strong electric field produced by a very high static voltage source. 🙂


   
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Larry Manson
(@larry-manson)
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Seems the real problem is an economical low to high voltage transformer! High voltage diodes are available for less than 50 cents.  But if you need 10 kv. The secondary is going to need lots of care to prevent breakdown. Breakdown voltage is just not there on wires. This kind of like a CRT TV flyback transformer but low current! Spacing. Encapsulation. Vaccum.

This post was modified 1 year ago 3 times by Larry Manson

   
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