Optimized design and process for making a DC voltage reference based on MEMS
A micromechanical moving plate capacitor has been designed and fabricated for use as a dc voltage reference. The reference is based on the characteristic pull-in property of a capacitive microelectromechanical system (MEMS) component. The design is optimized for stability. A new silicon-on-insulator (SOI) process has been developed to manufacture the component. We also report on improved feedback electronics and the latest measurement results.
Stability of a micromechanical pull-in voltage reference
The reproducibility over temperature and time of the pull-in voltage of micromechanical structures has been analyzed and verified using fabricated devices in silicon. The pull-in structures are intended for use as an on-chip voltage reference. Microbeams of 100-/spl mu/m length, 3-/spl mu/m width, and 11-/spl mu/m thickness are electrostatically actuated with a very reproducible pull-in voltage at 9.1 V. Devices demonstrated an initial drift of -12 mV over 10 days and stabilized within the 500-/spl mu/V measurement uncertainty. The measured temperature coefficient of -1 mV/K is in good agreement with the analysis and is due to the combined effect of thermal expansion and the temperature dependence of the Young's modulus in silicon.
Bodies of Evidence: Burial, Memory and the Recovery of Missing Persons in Cyprus
List of Figures and Maps Acknowledgements Chapter 1. Heirs of Antigone: Disappearances and Political Memory Chapter 2. Suppressed Experiences Chapter 3. Testimonies of Fragmentation, Recollections of Unity Chapter 4. The Missing as a Set of Representations Chapter 5. The Martyrdom of the Missing Chapter 6. L'image Juste, or Juste une Image? Chapter 7. Painting Absences, Describing Losses Chapter 8. Antigone's Doubt, Creon's Dilemma Chapter 9. Power, Complicity, and Public Secrecy Bibliography Appendices Index