{"id":1702,"date":"2026-04-07T10:20:33","date_gmt":"2026-04-07T10:20:33","guid":{"rendered":"https:\/\/www.mediainteractionlab.eu\/?page_id=1702"},"modified":"2026-04-08T17:21:21","modified_gmt":"2026-04-08T17:21:21","slug":"knitted-resonant-circuits-chi2026","status":"publish","type":"page","link":"https:\/\/www.mediainteractionlab.eu\/?page_id=1702","title":{"rendered":"Knitted Resonant Circuits CHI2026"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\"><strong>Knitted Inductive Flex Sensors for Wearable Applications<\/strong><\/h2>\n\n\n\n<p>In this CHI publication we present a <strong>knitted inductive bend sensor<\/strong> which seamlessly <strong>integrates a coil and a capacitor<\/strong> into a soft and flexible tubular knit. By knitting enameled copper wires, we form a self-supporting coil, whose inductance changes with <strong>stretching and bending<\/strong>. Knitting both a coil and a parallel-wire capacitor, we create a textile resonant LC circuit, while <strong>preserving the softness, elasticity, and breathability<\/strong> of knitted textiles.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Knitting Resonant Circuits (CHI 2026)\" width=\"640\" height=\"360\" src=\"https:\/\/www.youtube.com\/embed\/H9oDGTb95QM?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p>In a tubular knit, the yarn follows a <strong>helical path<\/strong>, which, when knitting thin enameled wires, allows for creating coils that are <strong>structurally self-supporting<\/strong>. This is in contrast to embroidered textile coils, which require a base textile and are usually flat. The sensing coils inductance changes the <strong>resonance frequency<\/strong> of an LC circuit. This frequency is measured and <strong>mapped to a bending angle <\/strong>of an enclosed joint, e.g. a knee or an elbow.<\/p>\n\n\n\n<p>The integration of the <strong>capacitor<\/strong> of the LC circuit directly into the knit aims towards <strong>fully integrated electronic textile sensors<\/strong>, potentially allowing for wireless sensing of the resonance frequency through <strong>electromagnetic coupling<\/strong>. Omitting the need for a wire connection to the read-out electronics, which is often a breaking point for electronic textiles, can extend durability and washability.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1788\" height=\"494\" src=\"https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig2.png\" alt=\"\" class=\"wp-image-1704\" style=\"aspect-ratio:3.619389666394978;width:678px;height:auto\" srcset=\"https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig2.png 1788w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig2-300x83.png 300w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig2-768x212.png 768w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig2-1536x424.png 1536w\" sizes=\"auto, (max-width: 1788px) 100vw, 1788px\" \/><figcaption class=\"wp-element-caption\">The diagram (A) shows a simplified wire path of the two knitted wires forming the resonant circuit, with a more detailed view shown (B). The equivalent circuit of the knit is shown in (C), a resonant LC circuit. (D) is showing the knitting pattern used for the capacitor and the coil.<\/figcaption><\/figure>\n<\/div>\n\n\n<p>We fabricate the knitted sensors using our industrial <strong>V-bed knitting machine<\/strong> ADF 530 K, evaluate sensor <strong>sensitivity and hysteresis<\/strong> over 100 bending cycles, and demonstrate the sensors versatility across joints of different radii. Through our tests we could demonstrate a <strong>hysteresis of 16\u00b0<\/strong> and a <strong>sensitivity<\/strong> measured through the resonance frequency shift of <strong>-2.39 kHz\/deg<\/strong>. Through mathematical modelling we could estimate the resonance frequency of a knitted circuit with 2.66 MHz comparing to the measured resonance frequency of 2.59 MHz. This allows us to design a sensor that fits the frequency range of our sensing hardware.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"2852\" height=\"654\" src=\"https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig3.png\" alt=\"\" class=\"wp-image-1705\" srcset=\"https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig3.png 2852w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig3-300x69.png 300w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig3-768x176.png 768w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig3-1536x352.png 1536w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig3-2048x470.png 2048w\" sizes=\"auto, (max-width: 2852px) 100vw, 2852px\" \/><figcaption class=\"wp-element-caption\">The graphs show the resonance frequency of the sensor dependent on the bending angle with 100 repetitions. (A) shows all repetitions, (B) shows a section of the test, and (C) shows the hysteresis over 100 bend cycles. (D) shows the test sensor at 90 degrees bending angle.<\/figcaption><\/figure>\n\n\n\n<p>We implemented <strong>knee and elbow sleeve<\/strong> prototypes to illustrate how the knitted resonant sensors can be integrated into wearables that can <strong>sense body motion<\/strong> and a joints <strong>bending angle<\/strong>. Knitted inductive flex sensors are most suitable for applications where bending needs to be measured in only one direction, as the<br>deformation of the coil cannot be distinguished directionally.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"377\" src=\"https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig4.png\" alt=\"\" class=\"wp-image-1706\" srcset=\"https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig4.png 600w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-fig4-300x189.png 300w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><figcaption class=\"wp-element-caption\">The knitted sensor worn on an elbow with the sensing data visualized on a smartphone.<\/figcaption><\/figure>\n<\/div>\n\n\n<p>The knitted LC circuit is a first step towards creating <strong>contactless sensing<\/strong> of fully knitted sensors. Our results show that knitted inductive sensors combine the wearability of soft textiles with the stability of inductive sensing, opening new sensing opportunities in healthcare, rehabilitation, and interactive electronic garments.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div class=\"wp-block-media-text is-stacked-on-mobile\"><figure class=\"wp-block-media-text__media\"><a href=\"https:\/\/raw.githubusercontent.com\/Media-Interaction-Lab\/presentations\/main\/2026-04-26-CHI%20Knitted%20Inductive%20Flex.pdf\"><img loading=\"lazy\" decoding=\"async\" width=\"1226\" height=\"800\" src=\"https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-paper-1.jpg\" alt=\"\" class=\"wp-image-1715 size-full\" srcset=\"https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-paper-1.jpg 1226w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-paper-1-300x196.jpg 300w, https:\/\/www.mediainteractionlab.eu\/wp-content\/uploads\/2026\/04\/chi2026-paper-1-768x501.jpg 768w\" sizes=\"auto, (max-width: 1226px) 100vw, 1226px\" \/><\/a><\/figure><div class=\"wp-block-media-text__content\">\n<p>M. A. Haberfellner, T. Preindl, A. Pointner, N. M\u00fcnzenrieder, and M. Haller. <a href=\"https:\/\/raw.githubusercontent.com\/Media-Interaction-Lab\/presentations\/main\/2026-04-26-CHI%20Knitted%20Inductive%20Flex.pdf\">Knitted Inductive Flex Sensors for Wearable Applications.<\/a> In&nbsp;Proceedings of the 2026 CHI Conference on Human Factors in Computing Systems Conference (CHI\u201926).<br><a href=\"https:\/\/doi.org\/10.1145\/3772318.3791445\">https:\/\/doi.org\/10.1145\/3772318.3791445<\/a><\/p>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Knitted Inductive Flex Sensors for Wearable Applications In this CHI publication we present a knitted inductive bend sensor which seamlessly integrates a coil and a capacitor into a soft and flexible tubular knit. By knitting enameled copper wires, we form a self-supporting coil, whose inductance changes with stretching and bending. [&hellip;]<\/p>\n","protected":false},"author":11,"featured_media":1730,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-1702","page","type-page","status-publish","has-post-thumbnail","hentry"],"_links":{"self":[{"href":"https:\/\/www.mediainteractionlab.eu\/index.php?rest_route=\/wp\/v2\/pages\/1702","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mediainteractionlab.eu\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.mediainteractionlab.eu\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.mediainteractionlab.eu\/index.php?rest_route=\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mediainteractionlab.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1702"}],"version-history":[{"count":18,"href":"https:\/\/www.mediainteractionlab.eu\/index.php?rest_route=\/wp\/v2\/pages\/1702\/revisions"}],"predecessor-version":[{"id":1746,"href":"https:\/\/www.mediainteractionlab.eu\/index.php?rest_route=\/wp\/v2\/pages\/1702\/revisions\/1746"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mediainteractionlab.eu\/index.php?rest_route=\/wp\/v2\/media\/1730"}],"wp:attachment":[{"href":"https:\/\/www.mediainteractionlab.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1702"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}