Printer makes functioning tools

[Mike O'Dell]

there are Rapid Prototyping Machines ("3D printers") that 
use SLS - selective laser sintering. the way the machine
works is not that different from the powder-frame machine
but the power is very finely-divided metal and the
"printhead" is a optical stage which focusses a non-trivial
laser on the surface. the metal fuses ("sinters") and the
resulting part is real metal. Titanium turns out to be
a good material for this process, and since it's bio-friendly,
custom-made implants are made using SLS Titanium. there
are a couple of "pro" design rags which cover this area
in depth, and the most recent cover article in one of them
is about the guy at the Bethesda Naval Hospital who runs 
their custom-fab facility. he was showing a custom-made
cranial replacement plate of SLS Titanium. turns out
it can be made porous enough that any gas trapped
below it during installation can escape, but then 
when treated with BMP (bone morphogentic protein),
they can get some real bonding with the remaining bone.

other bony body parts are being fabbed as well.

on a slightly related note, a group in Stockholm
reports that they just succeeded in growing a major
piece of replacement trachea for a guy with a huge
humor in his. they harvested his stem cells from
bone marrow and then grew the tissue on a "scaffold"
which defined the interior. the piece included the
"Y" split where the trachea branches to each lung,
so it was extra-tricky. they removed the scaffold
(probably better described as an "armature" actually)
and then implanted the replacement.  the new piece only 
took a few days to grow in the tissue lab,
and within like 3 days after surgery, the guy
was doing great. the graft had sealed and there
has been no hint of rejection or infection.

without the implant, the guy was completely doomed.
there were no tissue donors, and they had to get
the tumor out before *it* killed him. but they
needed replacement parts and the store wasn't
open on weekends, so they made one.

wow. just wow.

to quote from Paul Simon,

"This is the age of miracles and wonder,
this is the long distance call."

     -mo