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From: martinr@speedware.com.au (Martin Ravell)
Subject: Re: Synthetic Muscles
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References: <3jq61a$msg@newshound.uidaho.edu> <1995Mar15.214740.16884@news.vanderbilt.edu>
Date: Thu, 16 Mar 1995 05:04:49 GMT
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>
>In article <3jq61a$msg@newshound.uidaho.edu> horn931@goshawk.csrv.uidaho.edu (Doctor Horn) writes:
>>       Hello there. I have an idea for synthetic muscles. I envision a 
>>foam like substance that behaves like a muscle (i.e. contracts with 
>>sufficient force in the presence of electrical current. This could be 
>>molded into the shape of human muscles therby providing for an 
>>anotomically correct hand, arm whatever. These currents could 
>>concieveably come from the original nerves (i.e. prosthetic devices). 
>>There is already a guy in Ca working on the axon (nerve) to wire 
>>connection, All I need is the substance. Any Ideas??
>>
>
>I've heard of some work being done in the Netherlands with magneto-rheological
>fluids (sp?)  They change their viscosity under a magnetic field.  Perhaps
>filling bicep-shaped bag with this substance would be something to look
>into.  I'm very sorry that I haven't got any references for you.
>

There is a group of metals that could be used for this. Don't 
ask me their name its been a while since I looked at them. The
property of interest is that they have two shapes (impressed
during a type of tempering process if I remember correctly).
When you heat the stuff above a certain temperature it physically
changes to the second shape. Let it cool and it will change back
to the colder state's shape. Depending upon the alloy it can
change shape with considerable force.

The second nice property is that it is resistant to electricity, 
enough so that by passing a current through it you can heat it to
its critical temperature and thereby initiate the shape change.

Pretty neat huh!?

Only problem I can see is dissipating the heat so as the 'muscle' 
will contract. Maybe this is a use for those semiconductor
(peltier effect?) coolers that NASA dreampt up?




Regards

Marty








