Dynamic characteristics of membrane displacement of a bidirectional electromagnetic microactuator with microcoil fabricated on a single wafer

Using neural networks to model an electromagnetic-actuated microactuator

“…An experimental method utilizing a laser Doppler vibrometer ͑LDV͒ has been carried out to investigate both the static and dynamic responses of the electromagnetic microactuator in air. [6][7][8] It was found that the static responses agree well with the results from finite element analysis ͑FEA͒. 6 On the other hand, very complex and extensive computational time and effort are required to model the dynamic responses of the microactuator using FEA.…”

“…7 Complexities arise when the microactuator is actuated at the frequency that is larger than its resonance ͑i.e., Ͼ100 Hz for a particular microactuator͒ or when it is actuated in a medium where the squeeze film damping is dominant ͑i.e., water and diluted methanol in water͒. The behavior of the microactuator is influenced considerably by many parameters, including input current ͑I coil ͒, frequency ͑f b ͒, electromagnetic field, and fluid properties of the medium.…”

A high-bandwidth electromagnetic MEMS motion stage for scanning applications

“…Although a single-layer micromachined planar coil typically cannot generate a large enough magneto-static force for actuation, the Lorentz force can be used by properly designing the spatial interaction between the magnet and the magnetic field generated by the coil [18][19][20]. Lorentz force actuation using a single-layer coil has previously been shown to be more than adequate for MEMS actuation by a number of researchers [9,10,[12][13][14][15][16][17]. The biggest advantages of Lorentz force actuators are that they are bidirectional and have linear characteristics, which is critical from the viewpoint of precision motion control.…”

“…electrostatic-nonlinear, high voltage; thermal-slow response time; piezoelectric-hysteresis, difficult to deposit materials). A number of electromagnetic MEMS actuator designs have been reported in the literature over the last two decades [9][10][11][12][13][14][15][16][17]. However, none of these mechanisms simultaneously meet the requirements discussed above in terms of size, stiffness and bandwidth.…”

“…This claim will be discussed in more detail later in the paper. As a result, a vertical (out-of-plane) motion stage based on the Lorentz force actuation principle developed by others [9][10][11][12][13][14][15][16][17] has been designed with modifications to the microcoil, flexure mechanism and magnet in order to meet the desired specifications. The motion stage can perform bidirectional displacement that is proportional to the input current and can be controlled with high precision, even with open-loop operation.…”