Nanophotonic detection of nanomechanical structures for use toward mass sensing applications

  • Author / Creator
    Sauer, Vincent T K
  • Nanomechanical beam resonators show much promise for use in integrated on-chip mass sensing systems. This follows from their own very small masses and also their ability to store the mechanical energy of their oscillations to produce strong measurable mechanical response signals. To achieve higher mass sensitivities the size of these nanomechanical beams is decreasing and as a result the transduction of their mechanical motion is becoming more difficult. This follows from smaller nanomechanical devices operating at higher frequencies and with smaller ranges of motion. Nanophotonics is very well suited to measure devices with these properties in mind. Optical signals of nano-optomechanical system (NOMS) devices are not limited due to high frequency roll-off like traditional electronic measurement techniques, and they have exhibited very high mechanical displacement sensitivities. The nanophotonic transduction and actuation of nanomechanical cantilevers is demonstrated using integrated nanophotonic structures. Mach-Zehnder interferometer and nanophotonic racetrack resonator optical cavity transduction is demonstrated with good results for size independent nanomechanical cantilever beams. The devices are studied with the application of mass sensing in mind and multiplexed operation is demonstrated to mitigate the small capture area of individual nanomechanical beams. A nanostencil structure fabrication process is also developed using materials compatible with integrated optical systems. These overshield structures function to both protect the nanophotonic structures from uncontrolled analyte interactions along with removing the ambiguity of a mass loading event by eliminating uncertainty in mass loading location. This control of mass loading location can also be used to limit the deposition area of analyte on the beam to ensure maximum mechanical responsivity for each mass loading event. The NOMS detection method shows good promise for integrating nanomechanical beams into future mass sensing systems.

  • Subjects / Keywords
  • Graduation date
    Spring 2014
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.