Hybrid electronic-mechanical coupled resonators for sensing applications

Resonators are increasingly used in many applications, from sensing (e.g. air pollution monitoring) to time referencing and filtering, and their market is expected to grow significantly in the near future (e.g. augmented and virtual reality). While crystal oscillators still hold the largest market revenue share in for instance smartphones, they are bulky and expensive. This explains why MEMS resonators today are largely gaining in popularity; they can achieve higher frequencies and offer the potential for integration with microelectronic circuits, leading to a reduced cost and form factor (physical size), enhanced performance and new functionality (e.g. intelligent sensing). Among the different types of MEMS implementations, weakly coupled resonators (WCRs) have recently popped up as a very promising solution, mainly because of their extremely high sensitivity. To avoid the current drawbacks of purely mechanical WCRs, this project aims to fundamentally explore and demonstrate the feasibility of the novel concept of hybrid WCRs that consist of an electronic resonator coupled to one or more mechanical resonators. This allows easy tuning to manufacturing imperfections, and opens the path to full integration of sensing and readout, and hence small size and cost. Besides high sensitivity, the project will also optimize the hybrid WCR structures towards high resolution/SNR and high common-mode rejection of environmental variations, way beyond the current state of the art.