Fabrication of Integrated Optofluidic Devices in Silicon and PDMS for Refractive Index Sensing Applications

  • Mutasem Odeh

Student thesis: Master's Thesis

Abstract

Optofluidic devices explore and deploy the interaction between light and fluids to realize versatile, complex and adaptable systems. The implementation of optofluidic devices, pushed by the mature research fields of microfluidics and nanophotonics, has led to novel miniaturized fluidic sensors. The incomparable advantages of high sensitivities, low power and cost, allow them to be efficiently used as chemical and biochemical sensors. This thesis reports on the development, fabrication and demonstration of integrated optofluidic devices. The first part of the work focuses on the development of silicon-based nanophotonic devices which are intended for refractive index sensing applications. The aim of the work is to develop and optimize the fabrication processes needed to realize passive, edge-coupled, single-etched silicon-on-insulator (SOI) nanophotonic devices with subwavelength features. These structures can then be selectively released and/or bonded to microfluidic channels that can deliver the fluid analyte. The nanostructures are patterned using electron beam lithography (EBL) and defined using inductively coupled plasma reactive-ion etching (ICP-RIE). Next, a silica cladding is deposited using plasma enhanced chemical vapor deposition (PEVCD), then patterned with UV photolithography, isotopically etched with hydrofluoric acid (HF) and finally released with a critical point dryer (CPD). In order to add the microfluidic capability, a polydimethylsiloxane (PDMS) microfluidic channel is fabricated and bonded to the chip, allowing to fully characterize the sensing performance of different fabricated devices. The second part of the work is a demonstration of a gradient-index (GRIN) optofluidic waveguide using polydimethylsiloxane cured with a radial variation of temperature.
Date of AwardMay 2017
Original languageAmerican English
SupervisorMarcus Dahlem (Supervisor)

Keywords

  • Optofluidic Devices
  • Microfluidics
  • Nanophotonics
  • Fluidic Sensors
  • Refractive Index Sensing.

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