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陳雄章 (Shawn Chen)
陳雄章 (Shawn Chen)
Modeling of Scratch Drive Actuator and Performance Enhancement in Low-Voltage Region
Modeling of Scratch Drive Actuator and Performance Enhancement in Low-Voltage Region
抓爬式靜電微致動器之模擬及低電壓區輸出特性的改善
抓爬式靜電微致動器之模擬及低電壓區輸出特性的改善
An improved model is proposed to reduce the cost due to trial and error in selection of Scratch Drive Actuator (SDA) geometry, driving voltage and output force level. Besides, a novel SDA design to reduce driving voltage from at least 80 volts to 40 volts to get better reliability with comparable output is also proposed. It is assumed that the deformation and property of SDA is same along the width direction, as the main plate may be treated by a beam model. Governing equation based on Euler-Bernoulli beam is first constructed. Solving this equation with proper boundary conditions, key SDA characteristics can be determined analytically, such as non-contact length, priming voltage, deflection curve, output force, bending moment and stress. The output force just stated is the input of SDA dynamic model of single degree-of-freedom including friction. To verify proposed model, electroplated nickel SDA arrays of 80 micron in length and 65 micron in width with suspended spring are fabricated and tested. The average travel distance after 1500 input pulses from 80 to 120 volts are measured to be from 5.9 to 13.9 micron, while average measured output forces are from 12.4 to 30.2 micro-N per SDA. Deviations between simulated and measured results are less than 10%, showing the superior ability of the proposed integrated SDA model for better performance prediction.
An improved model is proposed to reduce the cost due to trial and error in selection of Scratch Drive Actuator (SDA) geometry, driving voltage and output force level. Besides, a novel SDA design to reduce driving voltage from at least 80 volts to 40 volts to get better reliability with comparable output is also proposed. It is assumed that the deformation and property of SDA is same along the width direction, as the main plate may be treated by a beam model. Governing equation based on Euler-Bernoulli beam is first constructed. Solving this equation with proper boundary conditions, key SDA characteristics can be determined analytically, such as non-contact length, priming voltage, deflection curve, output force, bending moment and stress. The output force just stated is the input of SDA dynamic model of single degree-of-freedom including friction. To verify proposed model, electroplated nickel SDA arrays of 80 micron in length and 65 micron in width with suspended spring are fabricated and tested. The average travel distance after 1500 input pulses from 80 to 120 volts are measured to be from 5.9 to 13.9 micron, while average measured output forces are from 12.4 to 30.2 micro-N per SDA. Deviations between simulated and measured results are less than 10%, showing the superior ability of the proposed integrated SDA model for better performance prediction.
A low-voltage scratch drive actuator (LVSDA) is also proposed here by incorporating flexible joint into the conventional rectangular SDA to improve performance in low-voltage region. Experimental results show that, at the same total plate length of 80 micron and width of 65 micron, the proposed LVSDA can be actuated as low as 40 volts, much lower than 80 volts, the minimum required input voltage of conventional SDA. From nonlinear finite element analysis conducted by CosmosWorks, yielding effect is found to be a critical factor. Before yielding, LVSDA can provide better performance than SDA at the same input voltage. However, the yielding stress in flexible joint would limit the achievable maximum output force in high-voltage region. By varying joint length, width, or location, LVSDA has been operated in low-voltage region where the conventional SDA can not be operated, and can still provide comparable performance as SDA in high-voltage region. The proposed LVSDA design can provide more flexibility in design selection to meet different performance requirements.
A low-voltage scratch drive actuator (LVSDA) is also proposed here by incorporating flexible joint into the conventional rectangular SDA to improve performance in low-voltage region. Experimental results show that, at the same total plate length of 80 micron and width of 65 micron, the proposed LVSDA can be actuated as low as 40 volts, much lower than 80 volts, the minimum required input voltage of conventional SDA. From nonlinear finite element analysis conducted by CosmosWorks, yielding effect is found to be a critical factor. Before yielding, LVSDA can provide better performance than SDA at the same input voltage. However, the yielding stress in flexible joint would limit the achievable maximum output force in high-voltage region. By varying joint length, width, or location, LVSDA has been operated in low-voltage region where the conventional SDA can not be operated, and can still provide comparable performance as SDA in high-voltage region. The proposed LVSDA design can provide more flexibility in design selection to meet different performance requirements.
[1] S. Chen and W. Hsu (November 2002). Reversible Stepwise Motion by a Novel Symmetric Scratch Drive Actuator, ASME International Mechanical Engineering Congress and Exposition, New Orleans, U.S.A..
[1] S. Chen and W. Hsu (November 2002). Reversible Stepwise Motion by a Novel Symmetric Scratch Drive Actuator, ASME International Mechanical Engineering Congress and Exposition, New Orleans, U.S.A..
[2] S. Chen, C. Chang, and W. Hsu (July 2010). Output Force Characterization of Scratch Drive Actuators with Flexible Joints, 5th Asia-Pacific Conference on Transducers and Micro-Nano Technology, Perth, West Australia.
[3] S. Chen, C. Chang, and W. Hsu, "Output Force Enhancement of Scratch Drive Actuator in Low-Voltage Region by Using Flexible Joint." Sensors and Transducers 2010, 115, 71-82.
[3] S. Chen, C. Chang, and W. Hsu, "Output Force Enhancement of Scratch Drive Actuator in Low-Voltage Region by Using Flexible Joint." Sensors and Transducers 2010, 115, 71-82.
[4] S. Chen, C. Chang and W. Hsu, “Improved model of rectangular scratch drive actuator.” Journal of Micro/Nanolithography, MEMS, MOEMS 2011, 10, 013016.
[4] S. Chen, C. Chang and W. Hsu, “Improved model of rectangular scratch drive actuator.” Journal of Micro/Nanolithography, MEMS, MOEMS 2011, 10, 013016.
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