Document Type



Optical tweezing is a modern physics technique which allows us to use the radiation pressure provided from laser beams to trap very small microscopic particles. In the last two decades optical tweezers have been used extensively in biophysics and atomic physics to study the building blocks of our world on the cellular and quantum levels. Our goal is to construct a dual beam optical tweezers for future undergraduate biophysical research. In this thesis we discuss how the construction and assembly of the dual beam optical tweezers is done from start to finish. Construction consisted of assembling a polarization maintaining laser. This was then split into two to create a dual beam effect. Directing both beams in symmetrical and equidistant paths with the help of optical elements, the beams were overlapped in a counter propagating orientation. Microscopes were then used to focus the lasers into the target flow cell. Another set of optics were used to image the inside of the flow cell so we could visualize the laser trapping. It was necessary to construct a custom compressed air system to isolate the optical table from surrounding vibration so that we can accurately measure the pico-newton scale forces that are observed in biological systems. In addition, the biomaterial flow system was designed to supply the flow cell with biological solutions essential for experimentation. Future plans for this project include developing the software in order to collect experimental data and run biophysics experiments. This optical tweezers apparatus will allow us to study potential cancer drug interactions with DNA at the single molecule level and be a powerful tool in promoting interdisciplinary research at the undergraduate level.



Thesis Comittee

Thayaparan Paramanathan (Thesis Mentor)

Jeff Williams

Edward Deveney

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Original document was submitted as an Honors Program requirement. Copyright is held by the author.

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