Research on a New Flat-Type High-Sensitivity Force Sensor Utilizing Resonance Frequency change by Axial Force

本文研究了一种利用轴向力引起共振频率变化的新型平板式力传感器，并通过有限元分析将加速度传感器作为其应用实例之一。所得结果总结如下：(1)采用一根弯曲振动杆及其面外模态作为力传感器，实现了高灵敏度。(2)施加的轴向力与共振频率的变化呈线性关系。(3)该传感器具有很高的质量因数，因为其支撑部分的振动位移大大减小。(4)实验结果表明，外加加速度与共振频率变化呈线性关系。(5)在第一和第二模式下，传感器灵敏度分别约为2800ppm /G和2150ppm/G。(6)通过设计一种支撑方法，可以大大减小来自其他轴的不良加速度的影响。(7)接近共振频率的杂散振动不是实验驱动的。今后应对传感器的温度特性进行检查。可以想象，利用电子电路技术的传统补偿方法可以解决这一问题。作为一个未来的课题，在已获得的结果的基础上，这种结构可以由单晶材料通过微加工技术产生。

In this research, a new flat-type force sensor utilizing the resonance frequency change by the axial force is studied, and the acceleration sensor is also considered as one example of its application, by the finite element analysis. The obtained results are summarized as follows.(1) High sensitivity is realized by using only one flexurally vibrating bar and its out-of-plane mode as the force sensor.(2) The applied axial force and the resonance frequency change have a linear relationship.(3) The sensor has a high quality factor because the vibration displacements at its support portions are extremely reduced.(4) The analysis results showing that the relationship between the applied acceleration and the resonance frequency change is linear were confirmed experimentally.(5) The sensor sensitivities of approximately 2,800ppm/G and 2150ppm/G were realized for the 1st and 2nd modes, respectively.(6) The influences of the undesirable acceleration from other axes can be considerably made small by devising a support method.(7) The spurious vibrations that approach the resonance frequency are not driven experimentally.The temperature characteristic of the sensor should be examined in the future. It is conceivable that this can be solved by the conventional compensation method using the electronic circuit technique. As a future subject, on the basis of the obtained results, this structure may be produced by micro-machining techniques from a single crystal material.