{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:20:35Z","timestamp":1760242835725,"version":"build-2065373602"},"reference-count":40,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2016,12,2]],"date-time":"2016-12-02T00:00:00Z","timestamp":1480636800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"MEXT Kakenhi","award":["15H05923"],"award-info":[{"award-number":["15H05923"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Touch sensing is a fundamental approach in human-to-machine interfaces, and is currently under widespread use. Many current applications use active touch sensing technologies. Passive touch sensing technologies are, however, more adequate to implement low power or energy harvesting touch sensing interfaces. This paper presents a passive touch sensing technique based on the fact that the human body is affected by the surrounding extremely low frequency (ELF) electromagnetic fields, such as those of AC power lines. These external ELF fields induce electric potentials on the human body\u2014because human tissues exhibit some conductivity at these frequencies\u2014resulting in what is called AC hum. We therefore propose a passive touch sensing system that detects this hum noise when a human touch occurs, thus distinguishing between touch and non-touch events. The effectiveness of the proposed technique is validated by designing and implementing a flexible touch sensing keyboard.<\/jats:p>","DOI":"10.3390\/s16122049","type":"journal-article","created":{"date-parts":[[2016,12,2]],"date-time":"2016-12-02T10:36:37Z","timestamp":1480674997000},"page":"2049","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["A Touch Sensing Technique Using the Effects of Extremely Low Frequency Fields on the Human Body"],"prefix":"10.3390","volume":"16","author":[{"given":"Hatem","family":"Elfekey","sequence":"first","affiliation":[{"name":"Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hany","family":"Bastawrous","sequence":"additional","affiliation":[{"name":"Electrical Engineering Department, Faculty of Engineering, The British University in Egypt, Cairo 11837, Egypt"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shogo","family":"Okamoto","sequence":"additional","affiliation":[{"name":"Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2016,12,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2416","DOI":"10.1109\/TCE.2009.5373818","article-title":"The multi-touch system with high applicability using tri-axial coordinate infrared LEDs","volume":"55","author":"Lee","year":"2009","journal-title":"IEEE Trans. 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