RESUMEN
By eliminating the influence of the substrate on parasitic thermal resistance, MEMS suspended structures become one of the accurate nanoscale thermoelectric performance evaluation devices. However, the process of MEMS suspended thermoelectric devices is complex, and its multilayer suspended structure is easy to fracture due to large stress. As a result, optimizing the design of suspended structures is critical in order to reduce manufacturing complexity and increase yield. In this study, finite element simulation is used to investigate the impacts of varying structures and sizes on the stress of MEMS suspended devices. The maximum stress and average stress of silicon nanomaterials are lowered by 90.89% and 92.35%, respectively, by optimizing the structure and size of the beams and nanobelt. Moreover, MEMS suspended devices of various structures are successfully manufactured. It not only increases the yield to more than 70% but also decreases the impact of strain on thermoelectric performance and can be used to create suspended devices with integrated silicon microstrips.
RESUMEN
Resonator-integrated optical gyroscopes have advantages such as all-solid-state, on-chip integration, miniaturized structure, and high precision. However, many factors deteriorate the performance and push it far from the shot-noise limited theoretical sensitivity. This paper reviews the mechanisms of various noises and their corresponding suppression methods in resonator-integrated optical gyroscopes, including the backscattering, the back-reflection, the polarization error, the Kerr effect, and the laser frequency noise. Several main noise suppression methods are comprehensively expounded through inductive comparison and reasonable collation. The new noise suppression technology and digital signal processing system are also addressed.
RESUMEN
In this study, we demonstrate a novel, to the best of our knowledge, integrated indium phosphide (InP) and silicon nitride (Si3N4) waveguide platform, which is based on interlayer coupling, to achieve heterogeneous integration of a photodetector and waveguide ring resonator firstly. In order to improve the gyro bias stability, the Si3N4 and InP waveguides were designed with a high polarization extinction ratio and ultra-low loss. Three-dimensional finite difference time domain methods are used to optimize the InP taper dimensions to provide efficient optical coupling between the Si3N4 and InP waveguides. The optical coupler with a length of 100 µm is designed to achieve optical coupling between the Si3N4 and InP waveguides while maintaining its state of polarization all the way from the taper waveguides. The coupling efficiency of the optimized interlayer coupler has been improved to about 99.5%.
RESUMEN
MEMS/NEMS resonators are widely studied in biological detection, physical sensing, and quantum coupling. This paper reviews the latest research progress of MEMS/NEMS resonators with different structures. The resonance performance, new test method, and manufacturing process of single or double-clamped resonators, and their applications in mass sensing, micromechanical thermal analysis, quantum detection, and oscillators are introduced in detail. The material properties, resonance mode, and application in different fields such as gyroscope of the hemispherical structure, microdisk structure, drum resonator are reviewed. Furthermore, the working principles and sensing methods of the surface acoustic wave and bulk acoustic wave resonators and their new applications such as humidity sensing and fast spin control are discussed. The structure and resonance performance of tuning forks are summarized. This article aims to classify resonators according to different structures and summarize the working principles, resonance performance, and applications.