Science Buddies: "Ask an Expert"

I am conducting a project on the tracking of particles undergoing Brownian Motion. I will be using a microscope and computer program written in Matlab to track these particles. Last year I accomplished tracking these particles on a two dimensional x and y plane. This year, I am trying to figure out a way to track the particles in three dimensional space. I conclude that I need something that will automatically adjust the focal plane of the microscope based on feedback from a computer program. The amount of focal plane adjustment will be small because the particle being tracked is viewed under a large magnification. An example would be a programmable servo motor that turns the focus knob of the microscope *NOTE: I think doing it his way would be too expensive*. I think a better solution might be to adjust the slide instead of the focus knob. Is there anything that you know that will let me do that? Thanks for your help.

Hi,

Are you sure you need to control the focal plane dynamically. Here is a formula for computing the Depth of Field:

http://industrial-microscope.olympus-gl ... _depth.cfm

Her is a patent describing a 3D microscope:

http://www.faqs.org/patents/app/20080291532

Here are papers on piezoelectric drives for focusing microscopes:

http://www3.interscience.wiley.com/jour ... 1&SRETRY=0

This paper looks highly relevant to your problem:

http://people.physics.illinois.edu/Selv ... acking.pdf

I hope this gets you started. Good luck for a great project!

Best regards,

Barrett L. Tomlinson

Thanks for the info