Mukundan Vikram, Pruitt Beth L
Mechanical Engineering Department, Stanford University, Stanford, CA 94305 USA.
J Microelectromech Syst. 2009 Apr 1;18(2):405-413. doi: 10.1109/JMEMS.2009.2013398.
We present design and experimental implementation of electrostatic comb-drive actuators in solutions of high conductivity relevant for biological cells. The actuators are operated in the frequency range 1-10 MHz in ionic and biological cell culture media, with ionic strengths up to 150 mMoles/L. Typical displacement is 3.5 μm at an applied peak-to-peak signal of 5V. Two different actuation schemes are presented and tested for performance at high frequency. A differential drive design is demonstrated to overcome the attenuation due to losses in parasitic impedances. The frequency dependence of the electrostatic force has been characterized in media of different ionic strengths. Circuit models for the electric double layer phenomena are used to understand and predict the actuator behavior. The actuator is integrated into a planar force sensing system to measure the stiffness of cells cultured on suspended structures.
我们展示了适用于生物细胞的高电导率溶液中静电梳齿驱动致动器的设计与实验实现。这些致动器在离子和生物细胞培养基中，于1 - 10 MHz频率范围内运行，离子强度高达150毫摩尔/升。在施加5V峰 - 峰值信号时，典型位移为3.5μm。提出并测试了两种不同的高频驱动方案的性能。一种差分驱动设计被证明可克服由于寄生阻抗损耗导致的衰减。已对不同离子强度介质中静电力的频率依赖性进行了表征。使用双电层现象的电路模型来理解和预测致动器行为。该致动器被集成到平面力传感系统中，以测量在悬浮结构上培养的细胞的刚度。
