Capacitively-coupled-power has been successfully used to drive microrobots in the MEMS area [11]. To achieve this, we treated the stators and rotor of the comb-drive actuator as a sequence of insulated electrodes, as shown in Figure 1. When different voltages are applied to the stators, Idelalisib mw the rotor, the stators and the handle layer form a capacitive circuit. The potential (Vr) induced on the rotor is determined by the voltages applied on the two stators using the following equation:Vr=V1C1+V2C2C1+C2+Cr(1)where V1 and V2 represent the applied voltages, and C1, C2 and Cr represent the capacitances. Although Vr is floating, its value can be definitely determined by Equation (1), i.e., it is dependent on V1 and V2. Possible variation of Vr may arise from the parasitic capacitance that exists in the device.
This issue can be removed by careful design to avoid any parasitic capacitance.If the voltages V1 and V2 are different, the voltage differences between Inhibitors,Modulators,Libraries the rotor and the low-voltage and high-voltage stators will be different. The voltage differences bring about different attraction Inhibitors,Modulators,Libraries forces on two sides of the rotor. Then, the rotor will be moved to the position where the balance between the mechanical and the electrostatic forces achieves.By Equation (1), the influence of Cr can be observed. As Cr approaches zero, then:Vr=V1C1+V2C2C1+C2(2)and Vr will be determined by V1, V2, C1 and C2. This can be achieved by removing the handle layer under the movable part and isolating the rotor’s anchors from the stators’ anchors. Extra etching and bonding processes are required to do so.
In this case, the asymmetric configuration of finger overlap is necessary to generate an initial difference between Inhibitors,Modulators,Libraries C1 and C2, and then an initial difference between |Vr �C V1| and |Vr �C V2|. Without the asymmetric configuration, the actuator will not be actuated. As Cr approaches infinity, then:Vr?V1C1+V2C2Cr(3)Namely, Vr will approach Inhibitors,Modulators,Libraries zero. This can be achieved by significantly increasing the areas of the rotor’s anchors. Batimastat It is easy to estimate Vr in this case. However, the excessive device area makes this case not suitable to be implemented. In this article, Cr was neither close to zero nor infinity, hence Equation (1) was used as the basic formula to obtain Vr.Note that when non-conductive materials are used to construct the springs of comb-drive actuators, Cr is determined by the area of the movable structure. Cr will never approach infinity. Equation (1) will also be used as the basic formula to obtain Vr.3.?Design and Analysis3.1. DesignAn asymmetric comb-drive actuator with different initial engagements, a1 and a2, between rotor and stator fingers on each side was designed http://www.selleckchem.com/products/Enzastaurin.html to achieve different initial C1 and C2, as shown in Figure 1.