Mukundan Vikram, Ponce Pierre, Butterfield Holly E, Pruitt Beth L
Department of Mechanical, Stanford University.
J Micromech Microeng. 2009 Jun 1;19(6):1-9. doi: 10.1088/0960-1317/19/6/065008.
Operation of electrostatic actuators in liquid media has various proposed applications, especially in biological environments. The devices are operated by modulating at a frequency higher than the relaxation rate of the ions in solution. We present circuit models based on electric double layer theories to obtain analytical expression for the frequency-dependent force response of electrostatic actuators in ionic media. The model has been compared with experimental measurements of actuation in media of conductivity spanning five orders of magnitude. Further, impedance spectroscopy is used to measure the values of the circuit models, which are compared with the experiments. These measurements also quantify the parasitic impedances in the devices. A conformal layer of Parylene-C is demonstrated as a passivation scheme for the electrodes in corrosive media. The heating effects due to parasitic impedances are also quantified by temperature measurements of devices in fluids.
静电致动器在液体介质中的运行有多种拟议的应用，尤其是在生物环境中。这些装置通过以高于溶液中离子弛豫速率的频率进行调制来运行。我们提出基于双电层理论的电路模型，以获得离子介质中静电致动器频率相关力响应的解析表达式。该模型已与电导率跨度达五个数量级的介质中的致动实验测量结果进行了比较。此外，使用阻抗谱来测量电路模型的值，并与实验进行比较。这些测量还量化了装置中的寄生阻抗。聚对二甲苯-C保形层被证明是一种用于腐蚀性介质中电极的钝化方案。寄生阻抗引起的热效应也通过流体中装置的温度测量进行了量化。
