Hi


> *     What is the range of forces (to the nearest order of magnitude)
> that can be applied with these tweezers?

      The typical force ~  pico Newtons(pN)
  The produced reaction force is F =  Q. nP/c
  Where
 C = velocity of light
 n= refractive index(changes between the object&surrounding)e.g 1.5
 P = beam power(momentum transferred from the laser beam~
                  few 10's of mW  e.g  20mw)
 Q = quality factor (~ between 0.03 and 0.1)


> *     Where might these be useful in the medical industry?

 to trap the  bio logical molecules
 to manipulate particles and cells
 as a bio- tool
 rotation of  objects
 building micro structures & nano structures

> *     Limitations and possible hazards in using this type of tweezers
> in a medical application.
  these intense beams can harm the healthy cells


 and one of the best article on Optical tweezers is

" Lights,action:Optical tweezers",Contemporary Physics 2002,Volume
43,number 4, pages 241-258.

 that answers most of your questions and should be very interesting in
this respect.

Best wishes,
Srikanth Lavu


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