轴向拉力对微梁质量传感器精度和热弹性阻尼的影响

针对存在轴向拉力的矩形截面微梁谐振式质量传感器中的质量传感灵敏度、热弹性阻尼以及最小检测质量等问题进行了深入的研究。推导了质量传感器在存在轴向拉力情况下的检测灵敏度、热弹性阻尼以及最小检测质量的表达式。揭示了轴向拉力对质量传感器的工作性能的影响机理。结果表明:轴向拉力会提高质量传感灵敏度;轴向拉力会降低谐振器的热弹性阻尼;轴向拉力可以使得质量传感器捕获更微小的检测质量。

Effects of axial pretension on the detecting accuracy and thermoelastic damping of micro-beam resonant mass sensors

An analytical study was carried out on the evaluation of mass sensitivity, thermoelastic damping and minimum detectable mass for resonant mass sensors of bridge configuration with axial pretension.Explicit expressions for mass sensitivity, thermoelastic damping and minimum detectable mass were derived.Proposed models were applied to examine the effect of axial pretension on the performance of mass sensors.The results of the presented study demonstrate that better device performances can be achieved by axial pretension, i.e., the presence of tensile axial stress could improve mass sensitivity, increase quality factor, and enable the mass sensor to detect ever smaller mass.