{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T15:24:24Z","timestamp":1772205864865,"version":"3.50.1"},"reference-count":32,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2021,7,16]],"date-time":"2021-07-16T00:00:00Z","timestamp":1626393600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000781","name":"European Research Council","doi-asserted-by":"publisher","award":["772539"],"award-info":[{"award-number":["772539"]}],"id":[{"id":"10.13039\/501100000781","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This article presents a 14-bit chipless RFID label which, in addition to classical identification feature, can be used as decimal numeric keypad, allowing the deployment of secure access control applications. A low-cost single layer label comprising 10 RF loop scatterers is used to code information in the frequency domain. In addition, each resonator is associated to a digit in the decimal number system, and the difference in the spectrum caused by the touch event is exploited for the detection of each key pressing. The shape of the resonators has been carefully selected to be both highly resonant and to show high sensitivity to the presence or absence of the human finger. The concept is validated by measurements in an office environment using an FCC compliant low-cost chipless reader and microstrip vivaldi antennas. Simple detection algorithms are proposed for both identification and touch sensing in real environment.<\/jats:p>","DOI":"10.3390\/s21144862","type":"journal-article","created":{"date-parts":[[2021,7,18]],"date-time":"2021-07-18T21:18:52Z","timestamp":1626643132000},"page":"4862","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Chipless RFID Label with Identification and Touch-Sensing Capabilities"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7007-8722","authenticated-orcid":false,"given":"Rahul","family":"Unnikrishnan","sequence":"first","affiliation":[{"name":"LCIS Laboratory, Grenoble INP, Universit\u00e9 Grenoble Alpes, Grenoble INP, LCIS, F-26000 Valence, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6455-0261","authenticated-orcid":false,"given":"Olivier","family":"Rance","sequence":"additional","affiliation":[{"name":"LCIS Laboratory, Grenoble INP, Universit\u00e9 Grenoble Alpes, Grenoble INP, LCIS, F-26000 Valence, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6355-9109","authenticated-orcid":false,"given":"Nicolas","family":"Barbot","sequence":"additional","affiliation":[{"name":"LCIS Laboratory, Grenoble INP, Universit\u00e9 Grenoble Alpes, Grenoble INP, LCIS, F-26000 Valence, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2671-8366","authenticated-orcid":false,"given":"Etienne","family":"Perret","sequence":"additional","affiliation":[{"name":"LCIS Laboratory, Grenoble INP, Universit\u00e9 Grenoble Alpes, Grenoble INP, LCIS, F-26000 Valence, France"},{"name":"Institut Universitaire de France, 75005 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,7,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Finkenzeller, K. (2003). RFID Handbook: Fundamentals and Applications in Contactless Smart Cards and Identification, Wiley and Sons. [2nd ed.].","DOI":"10.1002\/0470868023"},{"key":"ref_2","unstructured":"Perret, E. (June, January 28). Beyond standard identification solutions. Proceedings of the 2018 2nd International Union of Radio Science (URSI) Atlantic Radio Science Meeting (AT-RASC 2018), Gran Canaria, Spain."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Washiro, A. (2016, January 21\u201323). Electric RFID communication via human body. Proceedings of the 2016 IEEE International Conference on RFID Technology and Applications (IEEE RFID-TA 2016), Shunde, Guangdong, China.","DOI":"10.1109\/RFID-TA.2016.7750748"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Ahmed, S.V., and Kiran, V.T. (2019, January 7\u20138). Touch screen based restaurant automation system using zigbee. Proceedings of the 2019 International Conference on Recent Advances in Energy-efficient Computing and Communication (ICRAECC), Nagercoil, India.","DOI":"10.1109\/ICRAECC43874.2019.8994997"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Ervasti, M., Isomursu, M., and Leibar, I.I. (2011, January 15\u201316). Touch- and audio-based medication management service concept for vision. Proceedings of the 2011 IEEE International Conference on RFID-Technologies and Applications, Sitges, Spain.","DOI":"10.1109\/RFID-TA.2011.6068645"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1109\/TBCAS.2012.2201258","article-title":"A Touch Probe Method of Operating an Implantable RFID Tag for Orthopedic Implant Identification","volume":"7","author":"Liu","year":"2013","journal-title":"IEEE Trans. Biomed. Circuits Syst."},{"key":"ref_7","unstructured":"Noor, M.Z.H., Ismail, I., and Saaid, M.F. (2009, January 6\u20138). Bus Detection Device for the Blind Using RFID Applications. Proceedings of the 2009 5th International Colloquium on Signal Processing & Its Applications, Kuala Lumpur, Malaysia."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"4592","DOI":"10.1109\/TMTT.2015.2495298","article-title":"Gesture Sensing Using Retransmitted Wireless Communication Signals Based on Doppler Radar Technology","volume":"63","author":"Wang","year":"2015","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1145\/2897824.2925953","article-title":"Soli: Ubiquitous gesture sensing with millimeter wave radar","volume":"35","author":"Lien","year":"2016","journal-title":"ACM Trans. Graph."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Li, G., Zhang, R., Ritchie, M., and Griffiths, H. (2017, January 8\u201312). Sparsity-based dynamic hand gesture recognition using micro-Doppler signatures. Proceedings of the 2017 IEEE Radar Conference (RadarConf), Seattle, WA, USA.","DOI":"10.1109\/RADAR.2017.7944336"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"7593","DOI":"10.1109\/JSEN.2018.2859815","article-title":"Feature-Based Hand Gesture Recognition Using an FMCW Radar and its Temporal Feature Analysis","volume":"18","author":"Ryu","year":"2018","journal-title":"IEEE Sens. J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"33610","DOI":"10.1109\/ACCESS.2019.2903586","article-title":"Short-Range Radar Based Real-Time Hand Gesture Recognition Using LSTM Encoder","volume":"7","author":"Choi","year":"2019","journal-title":"IEEE Access"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1109\/MMM.2019.2915490","article-title":"Motion Sensing Using Radar: Gesture Interaction and Beyond","volume":"20","author":"Gu","year":"2019","journal-title":"IEEE Microw. Mag."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2850","DOI":"10.1002\/adma.201200137","article-title":"Paper-Based, Capacitive Touch Pads","volume":"24","author":"Mazzeo","year":"2012","journal-title":"Adv. Mater."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1344","DOI":"10.1109\/TIM.2019.2908507","article-title":"Metamaterial-Inspired Radio Frequency Based Touchpad Sensor System","volume":"69","author":"Memon","year":"2019","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1109\/JMEMS.2016.2593956","article-title":"Inkjet-Printed Electromagnet-Based Touchpad Using Spiral Resonators","volume":"25","author":"Choi","year":"2016","journal-title":"J. Microelectromech. Syst."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Li, H., Brockmeyer, E., Carter, E., Fromm, J., Hudson, S., and Patel, S. (2016, January 7\u201312). A technique for drawing functional battery-free wireless interfaces on paper. Proceedings of the 2016 CHI Conference (CHI\u201916) on Human Factors in Computing Systems, Silicon Valley, San Jose, CA, USA.","DOI":"10.1145\/2858036.2858249"},{"key":"ref_18","unstructured":"Li, H., Ye, C., and Sample, A.P. (2015, January 18\u201323). IDSense: A human object interaction detection system based on passive UHF RFID. Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems, New York, NY, USA."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Barbot, N., and Perret, E. (2017, January 19\u201326). Gesture recognition with the chipless RIFD technology. Proceedings of the 2017 32nd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Montreal, QC, Canada.","DOI":"10.23919\/URSIGASS.2017.8104990"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"502","DOI":"10.1109\/ACCESS.2019.2961691","article-title":"Chipless RFID Tag for Touch Event Sensing and Localization","volume":"8","author":"Shahid","year":"2020","journal-title":"IEEE Access"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Garbati, M., Siragusa, R., Perret, E., and Halope, C. (2015, January 17\u201322). Low cost low smapling noise UWB chipless RFID reader. Proceedings of the 2015 IEEE MTT-S Internationional Microwave Symposium (IMS 2015), Phoenix, AZ, USA.","DOI":"10.1109\/MWSYM.2015.7166944"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1109\/TAP.2016.2618480","article-title":"Contactless Characterization of Coplanar Stripline Discontinuities by RCS Measurement","volume":"65","author":"Rance","year":"2017","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1049\/el:19840120","article-title":"Analytical formulas for coplanar lines in hybrid and monolithic MICs","volume":"20","author":"Ghione","year":"1984","journal-title":"Electron. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1007\/s12243-013-0358-7","article-title":"Design rules for chipless RFID tags based on multiple scatterers","volume":"68","author":"Vena","year":"2013","journal-title":"Ann. Telecommun. Ann. T\u00e9l\u00e9communications"},{"key":"ref_25","unstructured":"Melia, G. (2013). Electromagnetic Absorption by the Human Body from 1\u201315 GHz. [Ph.D. Thesis, University of York]."},{"key":"ref_26","unstructured":"Nikolovski, M. (2018). Detailed Modeling of the Human Body in Motion to Investigate the Electromagnetic Influence of Fields in a Realistic Environment. [Ph.D. Thesis, Technische Universit\u00e4t]."},{"key":"ref_27","first-page":"25","article-title":"Dielectric properties of tissues and biological materials: A critical review","volume":"17","author":"Foster","year":"1989","journal-title":"Crit. Rev. Biomed. Eng."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2231","DOI":"10.1088\/0031-9155\/41\/11\/001","article-title":"The dielectric properties of biological tissues: I. Literature survey","volume":"41","author":"Gabriel","year":"1996","journal-title":"Phys. Med. Biol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2251","DOI":"10.1088\/0031-9155\/41\/11\/002","article-title":"The dielectric properties of biological tissues: II. Measurements in the frequency range 10 Hz to 20 GHz","volume":"41","author":"Gabriel","year":"1996","journal-title":"Phys. Med. Biol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2271","DOI":"10.1088\/0031-9155\/41\/11\/003","article-title":"The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues","volume":"41","author":"Gabriel","year":"1996","journal-title":"Phys. Med. Biol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2326","DOI":"10.1109\/TMTT.2016.2568180","article-title":"Temporal Separation Detection for Chipless Depolarizing Frequency-Coded RFID","volume":"64","author":"Ramos","year":"2016","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3356","DOI":"10.1109\/TMTT.2011.2171001","article-title":"Chipless RFID tag using hybrid coding technique","volume":"59","author":"Vena","year":"2011","journal-title":"IEEE Trans. Microw. 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