This paper presents an accurate and complete analysis of the dynamic performance of a V-shaped microactuator. This multi-physical coupling analysis is split into two steps: the electro-thermal sub-model for temperature distribution and the thermo-elastic sub-model for displacement. For the electro-thermal sub-model, a combination of the Chebyshev spectral method and the improved Euler method is utilized to predict the thermal dynamic behavior, where a piecewise partial differential equation exists. This method is found to have conditional stability which is dependent on time steps and number of points. Although a one-dimensional geometric model is used in it, the obtained temperature profile hardly shows a difference over time compared with that from the finite element method where a three-dimensional geometric model is established. The method’s calculation time is also sharply reduced. According to the forced vibration theory, the thermo-elastic sub-model is rebuilt regardless of the damping term. When applied to different voltages, the displacement of the actuator at a steady state is validated by an experiment and an ANSYS simulation. Furthermore, the result of the transient displacement also shows a good agreement with the ANSYS simulation.

Dynamic performance of microelectromechanical system (MEMS) electrothermal actuators is directly determined by thermal principle and thermal characteristics at microscale differed from macroscale. To study and deeply understand the heat transfer mechanism and dynamic behavior of the MEMS electrothermal actuators, dynamic thermal measurements of a U-shaped thermal actuator and its array are implemented in air by using an infrared thermal microscope system with high spatial resolution. Both the steady-state, transient and frequency response thermal measurements are thoroughly carried out for the actuators. The temperature distribution, heating and cooling performances, and frequency response at different waveform voltages are analyzed and discussed. Furthermore, the electro-thermo-structural coupling model is established and the simulated results are compared with the measured results including steady-state, transient and frequency response thermal performances. By qualitative and quantitative comparisons, the simulated results are in fairly good agreement with the measured results.

This letter reports an inertial microswitch with an integrated filtering mechanism to realize acceleration band-pass characteristics. The switch is composed of a normal acceleration threshold switch (a high-pass mechanism) and a specially designed filtering mechanism. Only acceleration between the upper and lower cut-off thresholds can make the switch transition to its `on' state. Both dynamic finite element simulations and experiments were performed to study the dynamic behavior of the switch. The results indicate that the acceleration band-pass characteristics have been successfully achieved. The upper and lower cut-off thresholds and bandwidth varied with shock duration. The experimental data agreed well with the simulated results.

This article introduces a novel micro-optical electromechanical system safety and arming (S&A) device that utilizes both electrothermal and centrifugal actuators to ensure the reliability and efficiency of the device. The S&A device comprises a pair of V-shaped latching actuators, a pair of U-shaped latching actuators, a reverse blocking actuator, a centrifugal alignment actuator, and two sets of status monitoring units. The V- and U-shaped latching actuators serve as safety features to prevent accidental triggering, while the centrifugal alignment actuator aligns the optical fibers. The mechanical responses of the device under dual-environment loads are analyzed using a finite element model, while a theoretical model is introduced to predict the centrifugal acceleration required for alignment. The device is fabricated using deep reactive ion etching on silicon-on-insulator wafers. Experimental tests confirm the effectiveness of the safety features and the device's capability to transmit high-power optical energy. The optical efficiency ranges from 71.8% to 76.4% (1.17–1.44 dB insertion loss), and the maximum power transfer is 902 mW from an 1180 mW input.

A novel self-latching MEMS optical interrupter with status monitoring is proposed to enhance the safety of laser initiation system (LIS) by preventing long-term heat accumulation and reducing response time. The electrothermal-actuated interrupter consists of an optical fiber alignment actuator, a positive latching actuator (PLA), and a reverse blocking actuator, each coupled with a status monitoring unit. The PLA is equipped with an interlock mechanism for self-latching capability. The interrupter’s operating state is monitored using cantilever beams that function as travel switches. The interrupters are fabricated using deep reactive ion etching (DRIE) on silicon-on-insulator (SOI) wafers. Experiments are conducted to study the behavior of the proposed interrupter, which demonstrates the successful implementation of its self-latching and status-monitoring features. The interrupter has a switching time of less than 64 ms and exhibits an optical efficiency ranging from 63% to 68% (1.67–1.97-dB insertion loss) with a maximum power transfer of 865 mW from a 1272-mW input.