A Passive Very Low-Frequency (VLF) Electric Field Imager

Hugh E. Chung, Weidong Ye, Sandeep G. Vora, Steve Rednour, David Allee

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


It is shown that an array of D-dot sensors can be implemented to not only detect, but for the first time, image very low-frequency electric fields. D-dot sensors sense current proportional to the time derivative of the electric field. The signal of interest is extracted from each D-dot pixel using a lock-in amplifier through an automated multiplexer. We have successfully rendered very low-frequency electric field images from energized wires using the proposed electric field imager. As a proof-of-concept, the arrays were fabricated on both a printed circuit board and a flexible polyethylene naphthalate substrate, the latter of which incorporates a thin-film transistor process. Such a device will have commercial and industrial applications, such as imaging sources of electromagnetic interference as well as security applications for noninvasive monitoring.

Original languageEnglish (US)
Article number7407603
Pages (from-to)3181-3187
Number of pages7
JournalIEEE Sensors Journal
Issue number9
StatePublished - May 1 2016


  • D-dot sensor
  • Flexible electronics
  • electric fields
  • imaging
  • sensor array
  • very low frequency

ASJC Scopus subject areas

  • Instrumentation
  • Electrical and Electronic Engineering


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