Micro-ring resonators based on silicon-on-insulator (SOI) waveguide are widely used as sensors due to their small size and high sensitivities. After being fabricated on an integrated photonic technology, it can be applied in bio-chemical analyses crucial for human health monitoring, disease diagnoses, etc.
In this project, we develop and construct a robust experimental setup based on the SOI based micro-ring resonator, which combines temperature control and modification of the waveguide cladding via surface treatments and microfluidic integration. The setup gives a controlled environment for characterizing the photonic chip under various chemical treatments or different physical ambient.
After the setup is built, several experiments were performed to test the optical characteristics of the ring resonator, under different scenarios. These include temperature control, treatment of chip surface with sodium chloride and glucose solutions at varying concentrations, and lastly chip-surface functionalization for biomarker detection. With these experiments (also validated by numerical simulations), we demonstrate the robustness and reliability of our setup.

Evaporation can induce acoustic emissions in microfluidic devices. The origin of these emissions and their damping remains elusive. This thesis studies acoustic emissions from 3D printed microfluidic tubes mimicking xylem vessels in plants. We show the time and frequency domain signature of these emissions. From these signatures, we identify three types of acoustic pulses. While the source of the first type remains elusive, the second type originates from our evaporative membrane and the third from slower events like microcracking. By varying the vessel's geometry, we observe that its frequency shifts down with increasing vessel radius and length for the second pulse type. We confirmed this behaviour using numerical simulations of the vessel. These findings provide new insights into evaporation induced acoustic emissions from microfluidic devices and, due to their similar morphology, xylem vessels in plants.