07/13/2023
By Zachary Kurland

The Kennedy College of Sciences, Department of Physics & Applied Physics, invites you to attend a Ph.D. dissertation defense by Zachary Kurland on, ”A novel electrophoretic technique to improve metasurface sensing of charged particles in solution."

Degree: Doctoral
Date: Tuesday, July 25, 2023
Time: noon
Location (hybrid): Pulichino Tong Building, Room 462; or contact zachary_kurland@student.uml.edu for Zoom link.


Committee Chair: Thomas Goyette, Department of Physics & Applied Physics, Submillimeter-wave Technology Laboratory, University of Massachusetts Lowell

Committee Members:

  • Prof. Viktor Podolskiy, Department of Physics & Applied Physics, University of Massachusetts Lowell
  • Prof. Timothy Cook, Department of Physics & Applied Physics, University of Massachusetts Lowell

Abstract

Metasurfaces have proven their utility in sensing applications where there is very little material of interest available for detection. Surrounding each metasurface aperture, there is a quantifiable region in which each aperture is most sensitive to changes in its ambient environment. However, the current method for sensing particles in solution allows the particles to sediment randomly on the metasurface due to evaporation of the suspending medium. Therefore, since each metasurface aperture only occupies a small fraction of the total surface area (and thus, the regions of greatest sensitivity are limited), it would be advantageous if one were able to force a material of interest to preferentially accumulate in the regions of greatest sensitivity.

A novel electrophoretic technique to improve the sensing capabilities of charged particles in solution is presented. The proposed technique may improve the ability of metasurfaces to sense charged particles in solution by forcing them to preferentially sediment within metasurface regions of greatest sensitivity. Such a technique may be useful in various sensing applications, such as in biological, polymer, or environmental sciences, where low concentration particles in solution are of interest. The electrophoretic technique was simulated and experimentally tested using latex nanoparticles in solution. The results suggest that, using this technique, one may theoretically increase the particle density within the metasurface regions of greatest sensitivity by nearly 1900% in comparison to random sedimentation due to evaporation. Such an increase in particle density within the regions of greatest sensitivity may facilitate more precise material property measurements and enhance identification and detection capabilities of metasurfaces to low concentration particles in solution. It was experimentally verified that the electrophoretic technique enabled the preferential gathering of latex nanoparticles within the most sensitive metasurface regions, resulting in 900% - 1700% enhancements in metasurface sensing capabilities.