Articles

Analytic torque model for two-axis microelectromechanical system mirrors

[+] Author Affiliations
Clinton L. Edwards

Johns Hopkins University, Applied Physics Laboratory, Mail Stop: 1E-154, 11100 Johns Hopkins Road, Laurel, Maryland 20723 and University of Maryland, 2369 AV Williams Building, College Park, Maryland 20742

Bradley G. Boone

Johns Hopkins University, Applied Physics Laboratory, Mail Stop: 2-155, 11100 Johns Hopkins Road, Laurel, Maryland 20723

William S. Levine

University of Maryland, College Park, Department of Electrical and Computer Engineering, 2369 AV Williams Building, College Park, Maryland 20742

Christopher C. Davis

University of Maryland, College Park, Department of Electrical and Computer Engineering, 2369 AV Williams Building, College Park, Maryland 20742

J. Micro/Nanolith. MEMS MOEMS. 6(4), 043012 (November 29, 2007). doi:10.1117/1.2816455
History: Received May 24, 2007; Revised August 12, 2007; Accepted August 16, 2007; Published November 29, 2007
Text Size: A A A

The availability of recently developed microelectromechanical system (MEMS) micro-mirror technology provides an opportunity to replace macroscale actuators for free-space laser beam steering in light detection and ranging and communication systems. Precision modeling of mirror pointing and its dynamics are critical to the design and control of MEMS beam steerers. Beginning with Hornbeck’s torque approach, we present a first-principles, analytically closed-form torque model for an electrostatically actuated two-axis (tip-tilt) MEMS mirror structure. The torque expression is a function of the mirror’s physical parameters, such as angles, voltages, and size. An Euler dynamic equation formulation describes the gimballed motion as a pair of damped harmonic oscillators with a coupled torsion function. Static physical parameters such as MEMS mirror dimensions and voltages are inputs to the model as well as dynamic harmonic oscillator parameters, such as damping and restoring constants, which are calculated or fitted to measurements. A Taylor series expansion of the torque function provides insights into MEMS behavior, including operational sensitivities near “pull-in.” MATLAB and SIMULINK simulations illustrate performance sensitivities, controllability, physical limitations, and other important considerations in the design of precise pointing systems. Commercial-off-the-shelf micromirror measurements confirm the model’s validity in steady state and dynamic scanning operations.

Figures in this Article
© 2007 Society of Photo-Optical Instrumentation Engineers

Citation

Clinton L. Edwards ; Bradley G. Boone ; William S. Levine and Christopher C. Davis
"Analytic torque model for two-axis microelectromechanical system mirrors", J. Micro/Nanolith. MEMS MOEMS. 6(4), 043012 (November 29, 2007). ; http://dx.doi.org/10.1117/1.2816455


Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Journal Articles

Related Book Chapters

Topic Collections

PubMed Articles
Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.