Capacitive transducers with curved electrodes
Capacitive transducers with curved electrodes
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带有弯曲电极的电容式传感器
DOI：
10.1109/jsen.2005.854137
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发表时间：
2006
影响因子：
4.3
通讯作者：
S. R. Patterson
中科院分区：
文献类型：
--
作者：
R. Mcintosh;P. Mauger;S. R. Patterson
介绍了弯曲电极电容式换能器的设计、性能和潜在应用。弯曲电极控制柔顺电极在外加应力下的偏转。一个电极上的电介质膜提供固定电极间距的可变区域。这种换能器的灵敏度和线性动态范围比平行电极的换能器更高、更宽。电学优势来自介电薄膜的介电常数，机械优势来自于其厚度。换能器是由硅膜片和聚合物膜构成的，硅膜片可以弯曲，聚合物膜可以在均匀压力下拉伸。硅传感器在125分贝的线性范围内测量动态压力变化。对于具有薄硅薄膜的传感器，获得了885%的电容变化。带有聚碳酸酯薄膜的传感器展示了低成本传感器测量压力、流体流量、位移和倾斜度的能力。研制了一种有源电容桥电路，用于在线测量电容变化达1000%，并通过力平衡反馈控制静电执行器。讨论了构建微尺度换能器的方法和材料，以及静电驱动的性能限制。
The design, performance, and potential applications are described for capacitive transducers with curved electrodes. A curved electrode governs the deflection of a compliant electrode under applied stress. A dielectric film on one electrode provides a variable region of fixed electrode spacing. The sensitivity and linear dynamic range of the transducers are higher and wider than devices with parallel electrodes. An electrical advantage is obtained from the permittivity of the dielectric film and a mechanical advantage from its thinness. Transducers have been constructed with silicon diaphragms that bend and polymer membranes that stretch in response to uniform pressure. The silicon sensors measured dynamic pressure changes over a linear range of 125 dB. An 885% change in capacitance was obtained for a sensor with a thin silicon diaphragm. Sensors with polycarbonate membranes demonstrated the ability of a low-cost transducer to measure pressure, fluid flow, displacement, and tilt. An active capacitive bridge circuit was developed to linearly measure capacitance changes up to 1000% and to control electrostatic actuators by force-balanced feedback. Methods and materials to construct microscale transducers are discussed along with the performance limitations of electrostatic actuation.