🚀 go-pugleaf

In article <Jan.4.22.43.27.1993.8155@planchet.rutgers.edu> gbloom@nyx.cs.du.edu (Gregory Bloom) writes:
>How hard is it to build an STM or AFM?  Does it seem like a project
>that could be made on the scale of 'The Amateur Scientist' series
>from Scientific American?

JoSH replies:
>[Homebrew STM's are a definite possibility;  the only one I've personally
> seen built was done by a couple of grad students in a lab here at
> Rutgers, though.

If I recall correctly, a year or two ago a high school student near
Stanford built one for his Science Fair project.  He used about $100
in parts.  The scan circuitry was scavenged from a discarded TV, so he
only had one scan rate available, but it was TV-compatible so he could
use an ordinary TV set for display.

STMs are therefore "easy" in some sense.  It would have been possible to
build one in the 1930s, if anyone had thought to do it.  You would have
had to use vacuum tubes for all the control, of course, but so what?

Be creative!  You might even come up with a better way of doing things
than anyone else!  This is still a young field.

>I have heard that getting the monatomic tipped probe
>is perhaps the hardest part.

One normal procedure for making tips, for a while, was to hold a piece of
wire against a belt sander.  Some reasonable fraction of the time this
gives you a good probe tip, and if it doesn't you can just try again.

Probe tips tend to become unusable fairly quickly (MTBF of hours at best),
so you need to have a way to get more inexpensively.  The most common failure
mechanisms are "head crashes" and the simple accumulation of "dirt".

	Howard A. Landman