Development of a microfluidic interface for suspended microchannel resonators

Suspended microchannel resonators (SMRs) are devices that detect particles in liquid samples. In comparison with similar resonating devices that must be immersed, SMRs allow the fluids to flow through microfluidic resonators. This principle of operation leads to a great reduction of the required sample and to enhanced quality factors. As such, SMRs show great potential for a variety of sensing applications. This thesis reports on the final steps of the microfabrication of SMRs and on the development of a microfluidic interface allowing the assembly and operation of those devices. The interface connector was drawn in SolidWorks before being fabricated. Two different techniques were then used. 3D-printing allowed for rapid prototyping of the connector, and different versions were produced. The final device was machined out of PMMA by the mechanical workshop. Sealing techniques were studied for vacuum operation of the SMRs. After reviewing a few different methods, we adopted an o-ring-based solution. In a similar manner, we selected fluidic connections that best suited the interface. Simulations were conducted to ensure the viability of our solution. In particular, the deformation of silicon nitride microchannel ceilings under o-ring compression was studied. Few experiments were performed with a 3D-printed connector, assembled to a simple PMMA lid and to an actual SMRs chip previously fabricated. It allowed us to evaluate the performances of 3D-printed devices and gain important insights in the assembly and handling of the fluid delivery system. Although the PMMA connector was not tested, it is expected to work admirably, as it possesses numerous advantages over its 3D-printed counterpart.