FORWARDED MAIL -------
From: micro@linknet.net (Chris Rambin)
Date: 05 Dec 97
Originally To: Rob Santilli 

Rob,

In response to your MEMS bulletin board request concerning nano-positioning
within a living cell,
I would like to propose a semi-mechanical approach.
The trapping of living cells with a focused laser beam has well established in
literature.
Most of the trapping methods employ IR lasers which yield a spot size far too
large of nano-increments of motion.
However the technique was developed so that the living cell is held stationary
while the instruments are moved around it.
Thus, if the an electrode were embedded in a standard microscope slide (i.e.
glass sample sheet) and the slide were attached to a standard  linear stage with
nano-meter increments  (i.e. Queensgate Instruments, Inc.), the cell could be
held by the focused laser beam while the slide and electrode slip underneath it.
Thereby, you could obtain increments of data collection on the order of 5 nm.

The idea of laser trapping is not new.
A. Ashkin first  reported trapping glass micro-spheres in 1970 using an argon
laser.
His work with others continued into the 1980's.
Much research has been done since then including the use of an excimer laser to
shoot a hole through a 10 um glass sphere held in place by an optical laser.
And obviously, I published a paper on the subject in the 1994 MEMS Conference
Proceedings.

If you need any further reference assistance concerning the topic of laser
positioning, just ask and I'll send some copies of the articles I have
available.


Chris Rambin

micro@linknet.net



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