A capacitive touch interface for passive RFID tags

Author

Sample, Alanson P. ; Yeager, Daniel J. ; Smith, Joshua R.

Author_Institution

Dept. of Electr. Eng., Univ. of Washington, Seattle, WA

fYear

2009

fDate

27-28 April 2009

Firstpage

103

Lastpage

109

Abstract

This paper presents a novel method for incorporating a capacitive touch interface into existing passive RFID tag architectures without additional parts or changes to the manufacturing process. Our approach employs the tag´s antenna as a dual function element in which the antenna simultaneously acts as both a low-frequency capacitive fringing electric field sensor and also as an RF antenna. To demonstrate the feasibility of our approach, we have prototyped a passive UHF tag with capacitive sensing capability integrated into the antenna port using the WISP tag. Finally, we describe how this technology can be used for touch interfaces as well as other applications with the addition of a LED for user feedback.

Keywords

UHF radio propagation; radiofrequency identification; tactile sensors; LED; RF antenna; WISP tag; capacitive touch interface; dual function element; low-frequency capacitive fringing electric field sensor; manufacturing process; passive RFID tags; passive UHF tag; radio frequency identification; user feedback; Active RFID tags; Capacitive sensors; Costs; Credit cards; Manufacturing processes; Passive RFID tags; RFID tags; Radiofrequency identification; Switches; UHF antennas; Passive RFID; capacitive sensor; touch interface; transponder;

fLanguage

English

Publisher

ieee

Conference_Titel

RFID, 2009 IEEE International Conference on

Conference_Location

Orlando, FL

Print_ISBN

978-1-4244-3337-7

Electronic_ISBN

978-1-4244-3338-4

Type

conf

DOI

10.1109/RFID.2009.4911212

Filename

4911212