Polydimethylsiloxane-based capacitive motion sensor and its read-out circuit


Yildirim O., BOZYEL İ., Saka K., KAYIKÇIOĞLU T., GÖKCEN D.

INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, vol.49, no.7, pp.2147-2157, 2021 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 49 Issue: 7
  • Publication Date: 2021
  • Doi Number: 10.1002/cta.3009
  • Title of Journal : INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS
  • Page Numbers: pp.2147-2157

Abstract

A capacitive motion sensor that can detect human walking and motions up to a certain distance was designed using polydimethylsiloxane (PDMS) as the primary sensor material. A read-out circuit was designed to detect capacitive coupling with the sensor material caused by the motion in the surrounding. The read-out circuit consists of sensing, filtering, and amplifying stages. A high-pass filter was used to avoid DC components, and to eliminate adverse impacts of 50Hz noise in the sensing signal, a sixth-order low-pass filter consisting of active Sallen-Key and passive RC filters was utilized. The signals obtained from the complete read-out circuit revealed that the sensor system could accurately detect human movements up to 2 m away. Also, different signal patterns were obtained from the output of the sensor system for various human motions.