石墨烯谐振式力学量传感器研究进展

Research progress of electromechanical graphene resonant sensors

传统谐振式传感器的谐振敏感元件大多采用金属、石英晶体、硅等材料制成,但随着谐振式传感器朝着小型化、微型化、实用化的趋势发展,不但要求新型谐振子材料可进行微纳加工,还对其灵敏度和精度提出了更高的要求.石墨烯这种新型二维纳米材料,因具有出色的力学、电学、光学、热学特性,在谐振传感领域有着巨大的应用潜力和研究价值,因此基于石墨烯材料的力学量传感器有望在小型化、高性能和环境适应性等多方面超越硅基力学量传感器.本文针对石墨烯谐振式力学量传感器,介绍了石墨烯材料的基本性质、制备与转移方法,阐述了谐振式传感器的工作原理与应用特点,进而分析了关于石墨烯谐振特性优化与谐振器制备的理论与实验研究;在此基础上,重点总结了石墨烯谐振器在压力、加速度、质量等传感器领域的研究进展,梳理了石墨烯谐振式力学量传感器在薄膜转移、结构制备与激振/拾振等方面的技术问题,同时也明确了石墨烯在谐振传感领域的研究价值和发展潜力.

The resonant sensor is a kind of high-sensitivity and high-stability sensor that directly outputs digital signals. The resonance sensitive elements of traditional resonant sensors are mostly made of metal, quartz crystal, silicon and other materials. However, with the development of resonant sensor toward the miniaturization and intellectualization, the sensitive materials of new resonator are micro-nano machined and highly sensitive. As a new type of two-dimensional nanomaterial, graphene has the great potentials in the field of resonance sensing because of its excellent mechanical, electrical, optical and thermal properties. Therefore,the mechanical quantity sensor based on graphene material is expected to surpass the silicon material mechanical quantity sensor in many aspects such as micro-nano size, high performance, and environmental adaptability. This review focuses on the graphene resonant mechanical quantity sensor. In the first part, we summarize the basic properties, preparation methods, and transfer methods of graphene materials. The preparation and transmission methods of graphene are key to high-performance graphene resonator, but there are still different problems in the preparation and transfer of graphene, which also greatly restricts the development of graphene resonator. In the second part, the basic theory of resonant sensors is given, and the common methods of transferring graphene films are introduced in detail. Then the theoretical and experimental studies of graphene resonator are discussed. For example, the theoretical studies of graphene resonator are investigated by using the classical elastic theory, non-local elastic theory, molecular structure mechanics and molecular dynamics. Then the effects of graphene preparation method, graphene layer number and shape,excitation and detection methods on the resonance performance are estimated in the resonant experiments of graphene resonators. After that, the research progress of graphene resonator is summarized in the fields of pressure, acceleration and mass sensors. Compared with traditional silicon resonators, graphene resonators have a small dimension and demonstrate preferable resonant performance under low-temperature and low-pressure conditions. In this case, the technical issues of graphene resonant sensor are introduced to emphasize the importance of suspended graphene film transfer, structure fabrication of harmonic oscillator and vibration excitation/detection of resonators, which contributes to the potential applications in the fields of aerospace,intelligent detection and biomedical sensing for graphene resonant sensors.