SciELO - Scientific Electronic Library Online

 
vol.10 issue1EditorialHeavy Tailed Network Delay: An Alpha-Stable author indexsubject indexsearch form
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

  • Have no similar articlesSimilars in SciELO

Share


Computación y Sistemas

Print version ISSN 1405-5546

Comp. y Sist. vol.10 n.1 México Jul./Sep. 2006

 

Design and Analysis of a MEMS Variable Capacitor using Thermal Actuators

 

Diseño y Análisis de un Capacitor Variable MEMS utilizando Actuadores Térmicos

 

José Mireles Jr1., Humberto Ochoa2 and Víctor Hinostroza3

 

Instituto de Ingeniería y Tecnología de la Universidad Autónoma de Ciudad Juárez Ave. Del Charro 450 N., Ciudad Juárez Chihuahua, México. CP 32310 TEL. +52 656 6884800, x4571 e–mails: Josemireles@ieee.org 1; Ochoa@ieee.org 2; Vhinostr@uacj.mx 3

 

Article received on April 06, 2006
Accepted on October 19, 2006

 

Abstract

We present the design and analysis of a MEMS variable capacitor coupled to thermal actuators. The variable capacitor is composed by two main components: 1) the capacitor built by two squared plates, which one plate is mechanically fixed to the substrate and the other is a moving plate having mechanical suspensions (springs) connected from each corner of it to the substrate, and 2) a set of thermal actuators that push the moving plate away from the substrate. Depending on the power applied on the thermal actuators, these would push up the variable plate from its sides, while the suspension pulls the plate down to the substrate for equilibrium. This work includes the design fabrication steps using PolyMUMPSTM process, and provides tables for the resulting values of the variable capacitors. The results accomplished using COVENTORWARETM software show that the variable capacitor has potential for automatic compensation of capacitances and for integration into frequency oscillators and filters.

Keywords: MEMS Design, MEMS FEA, Variable Capacitors, Thermal Actuators.

 

Resumen

En éste trabajo presentamos el diseño con tecnologías MEMS y análisis de un capacitor variable acoplado a actuadores térmicos. El capacitor variable está compuesto por dos componentes importantes: 1) el capacitor construído de dos capas cuadradas paralelas, en donde una placa está mecánicamente fija al sustrato y la otra es una placa movible la cual tiene resortes flexibles conectados de cada esquina de la placa al substrato, y 2) un arreglo de actuadores térmicos que separan la placa movible del substrato. Dependiendo de la potencia aplicada a los actuadores térmicos, éstos empujaran la placa variable por las secciones laterales para separar la placa del substrato, mientras que los resortes de suspensión contrarrestan la fuerza mecánica para mantener el equilibrio. Éste trabajo incluye los pasos de diseño y fabricación utilizando el proceso PolyMUMPSTM, y proporciona tablas de los resultados obtenidos destacando la funcionabilidad de los capacitares variables. Además, se presentan los resultados obtenidos utilizando el software COVENTORWARETM, donde mostramos el potencial de uso del capacitor variable para la realización de compensaciones automáticas de capacitancias dinámicas para la integración al desarrollo de osciladores de frecuencia y filtros.

Palabras clave: Diseño de MEMS, Análisis de elementos finitos de MEMS, capacitares variables, actuadores térmicos.

 

DESCARGAR ARTÍCULO EN FORMATO PDF

 

References

1. D.J. Young, and B.E. Boser, "A micromachined Variable Capacitor for Monolithic Low–Noise VCOs in Cellular Phone Application," Technical Digest of Solid–State Sensor and Actuator Workshop, Hilton Head Island, SC, USA, 1996, pp. 86–89.        [ Links ]

2. V. Jiménez, J. Pons, M. Domínguez, A. Bermejo, L. Castañer, H. Nieminen, and V. Ermolov, "Transient dynamics of a MEMS variable capacitor driven with a Dickson charge pump," Sensors and Actuators A 128 (2006) 89–97.        [ Links ]

3. Z. Xiao, W. Peng, R.F. Wolffenbuttel, and K.R. Farmer, "Micromachined variable capacitors with wide tuning range," Sensors and Actuators A 104 (2003) pp. 299–305.        [ Links ]

4. J.I. Seeger, and B.E. Boser, "Charge Control of Parallel–Plate, Electrostatic Actuators and the Tip–In Instability," Journal of Microelectromechanical Systems, Vol. 12, No. 5, October 2003        [ Links ]

5. J.I. Seeger, and B.E. Boser "Negative Capacitance For Control Of Gap–Closing Electrostatic Actuators" Transducers '03 The 12th International Conference an Solid State Sensors. Actuators and Microsystems, Boston, June 8–12 2003.        [ Links ]

6. W.C. Tang, M.G. Lim, and R.T. Howe, "Electrostatic Comb Drive Levitation and Control Method," Journal of Microelectromechanical Systems, Vol. 1, No. 4, December 1992.        [ Links ]

7. L. Che, B. Xiong, L. Dong, and Y. Wang, "Effects of bias voltage polarity on differential capacitive sensitive devices" Sensors and Actuators A 112 (2004) pp. 253–261.        [ Links ]

8. M. Handtmann, R. Aigner, A. Meekes, and G.H.M. Wachukta, "Sensitivity Enhancement of MEMS inertial sensors using negative spring and active control," Sensors and Actuators A 97–98 (2002) pp. 153–160.        [ Links ]

9. K.F. Harsh, B. Su, W. Zhang, V.M. Bright, and Y.C. Lee, "The realization and design considerations of a flip–chip integrated MEMS tunable capacitor," Sensors and Actuators 80 2000 pp. 108–118.        [ Links ]

10. G.T.A. Kovacs, "Micromachined Transducers Sourcebook" McGraw–Hill Companies, Inc. 1998, ISBN 0–07–290722–3.        [ Links ]

11. S.D. Senturia, "Microsystem Design," Kluwer Academis Publishers, ISBN 0–7923–7246–8.        [ Links ]

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License