Design and Modeling of Polysilicon Electrothermal Actuators for a MEMS Mirror with Low Power Consumption
| Autor: | Marco A. Escarola-Rosas, Francisco López-Huerta, Agustín L. Herrera-May, Adrian Herrera-Amaya, Moisés Vázquez-Toledo, L. A. Aguilera-Cortés, M. Lara-Castro |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
lcsh:Mechanical engineering and machinery electrothermal actuators 02 engineering and technology 01 natural sciences Thermal expansion Article 010309 optics endoscopic optical-coherence tomography 0103 physical sciences lcsh:TJ1-1570 Electrical and Electronic Engineering Microelectromechanical systems business.industry microelectromechanical systems (MEMS) mirror polysilicon SUMMiT V Mechanical Engineering Electrical engineering Biasing 021001 nanoscience & nanotechnology Thermal conduction Control and Systems Engineering Optoelectronics 0210 nano-technology business Actuator Beam (structure) Voltage DC bias |
| Zdroj: | Micromachines Micromachines; Volume 8; Issue 7; Pages: 203 Micromachines, Vol 8, Iss 7, p 203 (2017) |
| ISSN: | 2072-666X |
| Popis: | Endoscopic optical-coherence tomography (OCT) systems require low cost mirrors with small footprint size, out-of-plane deflections and low bias voltage. These requirements can be achieved with electrothermal actuators based on microelectromechanical systems (MEMS). We present the design and modeling of polysilicon electrothermal actuators for a MEMS mirror (100 μm × 100 μm × 2.25 μm). These actuators are composed by two beam types (2.25 μm thickness) with different cross-section area, which are separated by 2 μm gap. The mirror and actuators are designed through the Sandia Ultra-planar Multi-level MEMS Technology V (SUMMiT V®) process, obtaining a small footprint size (1028 μm × 1028 µm) for actuators of 550 µm length. The actuators have out-of-plane displacements caused by low dc voltages and without use material layers with distinct thermal expansion coefficients. The temperature behavior along the actuators is calculated through analytical models that include terms of heat energy generation, heat conduction and heat energy loss. The force method is used to predict the maximum out-of-plane displacements in the actuator tip as function of supplied voltage. Both analytical models, under steady-state conditions, employ the polysilicon resistivity as function of the temperature. The electrothermal-and structural behavior of the actuators is studied considering different beams dimensions (length and width) and dc bias voltages from 0.5 to 2.5 V. For 2.5 V, the actuator of 550 µm length reaches a maximum temperature, displacement and electrical power of 115 °C, 10.3 µm and 6.3 mW, respectively. The designed actuation mechanism can be useful for MEMS mirrors of different sizes with potential application in endoscopic OCT systems that require low power consumption. |
| Databáze: | OpenAIRE |
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