Homebrew PCBs

At 3:14 am ((PDT)) Mon Sep 24, 2007, Stefan Trethan wrote:

>Saw a novel use for PCBs yesterday on Mythbusters.
>
>They had to get past a fingerprint lock.
>
>The way they did it was lift a fingerprint, scan it, touch it up, etch
>a PCB from the image, and then cast latex or gelatine over it to make
>a 3D finger.

>[snip] They used photoprocess by the way, and FeCl.

If they had used something like gelatine-dichromate, they could
probably have omitted the copper etch by producing a relief
direct in gelatine. A tanning developer and gelatine removal is also
a way of making artistic (and very durable) photo prints.


Regards, LenW