Peter Todd wrote:
>>> Unfortunately in this case the device is going to be battery powered,
>>> so heaters are totally out, well, almost, plutonium powered heaters
>>> would last long enough... :)
>> What's your budget?  :)
> 
> I've heard the last time Nasa needed some plutonium for electrical
> generation on one of their probes even they couldn't get enough due to a
> slowdown in work at Sandia Labs due to a security incident.
> 
> That said, I hear depleted uranium is something they're trying to give
> away, not that I've ever found a nice online store to buy a kilo of it.
> Love some to go on my keychain next to my tritium glow stick, sutably
> encapsulated of course, it is a chemically toxic heavy metal after all.

Details, details...

>> Can you bond the display flush to the box wall with some clear adhesive? 
>>   Or cast the display face in resin to make a piece that could bond 
>> flush with the display wall?  Then you could conformal coat the rest of it.
> 
> It's an interesting idea... but it could add a lot of complexity. One of
> the more "interesting" things about the displays I'm using, the
> ChLCD "electronic paper" displays from Kent Displays, is that they are
> very pressure sensitive. If you touch them at all they leave a ugly
> visible mark that won't go away until you do an electronic clear.

Very cool modules!  How much do they cost?

> So in the case of the fully encapsulated option the thickness of resin
> was going to be fairly thick, at least half an inch, maybe more, to
> resist flexing. Any mechanical pressure on the encapsulation would be
> immediately transmitted to the display surface.

And you would hope the display wasn't flexed somehow while the resin was 
cooling?  Or would that be corrected once it started running?

> If there is an airspace between the display face and the enclosure
> things get much easier.
> 
> Not to say it isn't doable, but it's a lot more work, and then I have to
> worry about stuff like bonding the polyester resin to the acrylic making
> up the rest of the enclosure.

What about a clear oil or petroleum jelly instead of glue?  Get the 
mechanical placement using something else?

I mean, silica gel might just be sufficient and is much simpler.  And if 
it's completely sealed, you'd think the gel would absorb the water and 
then you'd be done.
-- 
Timothy J. Weber
http://timothyweber.org
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