Characterization of ESD Risk for Wearable Devices

Jianchi Zhou*, Kaustav Ghosh, Shaojie Xiang, Xin Yan, Ahmad Hosseinbeig, Jongsung Lee, David Pommerenke

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The core difference between the posture assumed for IEC 61000-4-2 human metal discharge and a discharge to a wearable device is the impedance between the charged body and the grounded structure discharged to. Especially for a waist-worn device, a larger portion of the body is close to the grounded structure; thus the geometry forms much lower impedance which will lead to higher currents. Despite the variability for the air discharge, in most cases, the current will be higher than 3.75 A/kV as specified for contact mode electrostatics discharge (ESD) calibration. Even for the most slowly rising discharges having a spark length equal to the value given by Paschen's law, a 10 kV ESD from the waist will surpass 37.5 A for a waist-worn metal part discharged (e.g., to a door frame). Modeling the wearable device discharge provides predictions on the current derivative and the transient field a wearable device is subjected to. Observed failure levels of a wearable electronic device and comparing discharges according to the IEC 61000-4-2 test standard against discharges from the device while wearable showed that the IEC set-up may be insufficient to ensure the robustness of the wearable devices.

Original languageEnglish
Pages (from-to)1313-1321
Number of pages9
JournalIEEE Transactions on Electromagnetic Compatibility
Issue number5
Publication statusPublished - 1 Oct 2018
Externally publishedYes


  • Electrostatic discharge
  • modeling
  • soft failure
  • wearable device

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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