SAW-based capacitive sensor with hemispherical electrode for nano-precision gap measurement

J. G. Kim, T. J. Lee, N. C. Park, Y. P. Park, K. S. Park, S. C. Lim, W. S. Ohm

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


Nano-precision gap measurement in the sub-micron range presents its own unique engineering challenge. The popular capacitive sensor platform, for example, is susceptible to the erroneous effect of electrode tilting and high noise floor, both of which are exacerbated by the small form factor required of a nano-precision gap sensor. In this paper, a capacitive gap sensor with a hemispherical electrode, used in combination with a SAW filter is presented. The proposed system outperforms the existing ones on two fronts. First, the system is virtually immune to the effect of electrode tilting due to the improved capacitor geometry. Second, it benefits from the outstanding signal conditioning capability of the SAW filter. Construction and characterization of a SAW-based capacitive gap sensor having resolution as fine as 10 nm are described.

Original languageEnglish
Pages (from-to)54-60
Number of pages7
JournalSensors and Actuators, A: Physical
Issue number1
Publication statusPublished - 2010 Sept

Bibliographical note

Funding Information:
This work was supported by National Research Foundation of Korea ( NRF-2009-0076065 ).

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering


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