[sdiy] Peratech force sensors (was Wireless World Chatterbox pdfs?)

[Steve Lenham]

From: "Paul Perry":

> That's a damn shame.
> I still don't believe that they work the way they think they do.
> In any case, they are just elastomer with tiny (very tiny) nickel
> spheres mixed in.

While the principle looks the same as standard carbon-loaded elastomers, one 
difference seems to be that the quantum effects give a much lower minimum 
resistance when the material is compressed - less than an ohm, they say. So 
it can be used directly in "power" applications.

> Perhaps someone can find some "prior art" & then we can make our own!!

Hmm...charcoal and silicone window sealant? ;-)

> Alternatively, there is the kind of force sensor that is made from
> a layer of tiny pyramids on a substrate that flatten with pressure &
> increase
> contact area with a covering conductive layer.
> I can't remember who makes these.. they aren't terribly cheap, though.

The attraction of the Peratech parts was that they were a) available through 
distribution and b) reasonable affordable. Neither is true now :-(

Cheers,

Steve L.