{"683281":{"#nid":"683281","#data":{"type":"news","title":"Stitched for Strength: The Physics of Stiff, Knitted Fabrics","body":[{"value":"\u003Cp dir=\u0022ltr\u0022\u003E\u003Ca href=\u0022https:\/\/physics.gatech.edu\/\u0022\u003ESchool of Physics\u003C\/a\u003E Associate Professor\u0026nbsp;\u003Ca href=\u0022https:\/\/physics.gatech.edu\/user\/elisabetta-matsumoto\u0022\u003E\u003Cstrong\u003EElisabetta Matsumoto\u003C\/strong\u003E\u003C\/a\u003E is unearthing the secrets of the centuries-old practice of knitting through experiments, models, and simulations. Her goal? Leveraging knitting for breakthroughs in advanced manufacturing \u2014 including more sustainable textiles, wearable electronics, and soft robotics.\u0026nbsp;\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EMatsumoto, who is also a principal investigator at the\u0026nbsp;\u003Ca href=\u0022https:\/\/wpi-skcm2.hiroshima-u.ac.jp\/\u0022\u003EInternational Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2) at Hiroshima University\u003C\/a\u003E, is the corresponding author on a new study exploring the physics of \u2018jamming\u2019 \u2014 a phenomenon when soft or stretchy materials become rigid under low stress but soften under higher tension.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EThe study, \u0022\u003Ca href=\u0022https:\/\/journals.aps.org\/pre\/abstract\/10.1103\/g94g-c6tt\u0022\u003EPulling Apart the Mechanisms That Lead to Jammed Knitted Fabrics\u003C\/a\u003E,\u0022 was published this week in\u0026nbsp;\u003Ca href=\u0022https:\/\/journals.aps.org\/pre\/\u0022\u003E\u003Cem\u003EPhysical Review E\u003C\/em\u003E\u003C\/a\u003E, and also includes Georgia Tech Matsumoto Group graduate students\u0026nbsp;\u003Ca href=\u0022https:\/\/physics.gatech.edu\/user\/sarah-gonzalez\u0022\u003E\u003Cstrong\u003ESarah Gonzalez\u003C\/strong\u003E\u003C\/a\u003E and\u0026nbsp;\u003Ca href=\u0022https:\/\/physics.gatech.edu\/user\/alexander-cachine\u0022\u003E\u003Cstrong\u003EAlexander Cachine\u003C\/strong\u003E\u003C\/a\u003E in addition to former postdoctoral fellow\u0026nbsp;\u003Ca href=\u0022https:\/\/engineering.tamu.edu\/materials\/profiles\/Michael-Dimitriyev.html\u0022\u003E\u003Cstrong\u003EMichael Dimitriyev\u003C\/strong\u003E\u003C\/a\u003E, who is now an assistant professor at Texas A\u0026amp;M University.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EThe work builds on the group\u2019s previous research demonstrating that\u0026nbsp;\u003Ca href=\u0022https:\/\/research.gatech.edu\/unraveling-physics-knitting\u0022\u003Eknitted materials can be mathematically \u2018programmed\u2019 to behave in predictable ways\u003C\/a\u003E. \u201cThese properties are intuitively understood by people who knit by hand,\u201d Matsumoto says, \u201cbut in order to manipulate and use these behaviors in an industrial setting, we need to understand the physics behind them. This new research is another step in that direction.\u201d\u003C\/p\u003E\u003Ch3\u003E\u003Cstrong\u003EAn Unexpected Twist\u003C\/strong\u003E\u003C\/h3\u003E\u003Cp dir=\u0022ltr\u0022\u003EGonzalez, who led the research, first became interested in jamming while conducting adjacent research. \u201cI was using model simulations to characterize how different yarn properties affect the behavior of knitted fabrics and noticed a strange stiff region,\u201d she recalls. \u201cIn our\u0026nbsp;\u003Ca href=\u0022https:\/\/www.nature.com\/articles\/s41467-024-46498-z\u0022\u003Eprevious research\u003C\/a\u003E, we had also seen this behavior in lab experiments, which suggested that what we were seeing in the simulations was a genuine phenomenon. I wanted to investigate it further.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EAfter digging into the topic, she realized that what she was seeing was called \u2018jamming.\u2019 In knits, Gonzalez explains, jamming occurs when stitches are packed tightly together, and the fabric resists stretching. Although it\u2019s a well-known phenomenon, the physics has mostly been investigated in granular systems, like snow or sand, rather than fabrics.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cIn fabrics, when you pull softly, the response is surprisingly stiff, but when you start pulling harder and harder, the stitches rearrange, and the material softens,\u201d Matsumoto says. \u201cIn granular systems, this is a little like how avalanches work. At low forces, the snow pack is solid, but when the slope is steep, the force of gravity liquidizes that snow pack into an avalanche.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cIn fabrics, it is a little like having a tangle in a piece of jewelry,\u201d she adds. \u201cIf you pull on it, it gets quite stiff, but if you loosen the knot, the chain can reconfigure, and it\u0027s not so stiff.\u201d\u003C\/p\u003E\u003Ch3\u003E\u003Cstrong\u003EUnraveling the Physics of Jamming\u003C\/strong\u003E\u003C\/h3\u003E\u003Cp dir=\u0022ltr\u0022\u003EUsing a combination of experiments with industrially knitted fabrics and computer models, the team analyzed what causes jamming in fabrics and how to control it. \u201cWe wanted to determine how different yarn properties impacted jamming,\u201d Gonzalez explains. \u201cOur goal was to understand the mechanics of jamming through how yarn interacts at various touchpoints in stitches.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EThe team found that both machine tension and yarn thickness played a key role in making a fabric more or less jammed, and that jamming behaves differently depending on which direction the fabric is stretched.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cWhen you stretch a knit along the rows, the stiffness of the yarn causes fabric jamming. Jamming in the other direction is due to yarn contacts,\u201d says Gonzalez. \u201cWe also showed that the impacts of changing machine tension and yarn thickness differ depending on fabric direction.\u201d\u0026nbsp;\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cDiscovering that fabric jamming works differently in different directions was a key insight,\u201d she adds. \u201cTo our knowledge, the physics of this has never been explored before.\u201d\u003C\/p\u003E\u003Ch3\u003E\u003Cstrong\u003EModern Innovation \u2014 With a Centuries-Old Technique\u003C\/strong\u003E\u003C\/h3\u003E\u003Cp dir=\u0022ltr\u0022\u003EThe research dovetails with Matsumoto\u2019s WPI-SKCM2 Center work,\u0026nbsp;which involves investigating fundamental aspects of knots and chirality.\u0026nbsp;The Center is interested in a class of materials called \u201cknotted chiral meta matter\u201d that could lead to more sustainable materials.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EFor example, knitting \u2014 which leverages chiral knots \u2014 could be used to create more elastic fabrics from natural materials. \u201cIn many cases, manufacturers use yarns that combine, for example, polyester, cotton, and elastane to create a desired elasticity,\u201d Matsumoto says. \u201cOur research suggests that manipulating the topology of the stitches could lead to a similar elasticity, reducing the need for petroleum-based fibers and creating a more sustainable textile.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cKnitting has the potential to be extremely useful in manufacturing, but knowledge has typically been shared through intuition and word of mouth,\u201d she adds. \u201cBy creating these mathematical models, we hope to formalize that knowledge in a way that\u2019s accessible for large-scale manufacturing \u2014 so we can leverage this centuries-old intuition for modern innovation.\u201d\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u003Cem\u003EFunding: This work was supported by the World Premier International Research Center Initiative (WPI), Ministry of Education, Culture, Sports, Science and Technology of Japan; National Science Foundation (NSF); and Research Corporation for Science Advancement (RCSA).\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EDOI:\u0026nbsp;\u003C\/em\u003E\u003Ca href=\u0022https:\/\/doi.org\/10.1103\/g94g-c6tt\u0022\u003E\u003Cem\u003Ehttps:\/\/doi.org\/10.1103\/g94g-c6tt\u003C\/em\u003E\u003C\/a\u003E\u003Cem\u003E\u0026nbsp;\u003C\/em\u003E\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EResearchers in the School of Physics unravel the secrets of the centuries-old practice of knitting in a new study that explores the physics of \u2018jamming\u2019 \u2014 a phenomenon when soft or stretchy materials become rigid under low stress but soften under higher tension.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Physicists unravel the secrets of the centuries-old practice of knitting in a new study that explores the physics of \u2018jamming\u2019 \u2014 a phenomenon when soft or stretchy materials become rigid under low stress but soften under higher tension."}],"uid":"35599","created_gmt":"2025-07-25 15:34:08","changed_gmt":"2025-07-30 12:38:14","author":"sperrin6","boilerplate_text":"","field_publication":"","field_article_url":"","location":"Atlanta, GA","dateline":{"date":"2025-07-25T00:00:00-04:00","iso_date":"2025-07-25T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"677487":{"id":"677487","type":"image","title":"Former Matsumoto Group member Krishma Singal operates a knitting machine used to create fabric samples for a previous study. Singal recently graduated from Georgia Tech with her Ph.D. (Photo Credit: Allison Carter)","body":"\u003Cp\u003EFormer Matsumoto Group member Krishma Singal operates a knitting machine used to create fabric samples for a previous study. Singal recently graduated from Georgia Tech with her Ph.D. (Photo Credit: Allison Carter)\u003C\/p\u003E","created":"1753457848","gmt_created":"2025-07-25 15:37:28","changed":"1753457848","gmt_changed":"2025-07-25 15:37:28","alt":"Former Matsumoto Group member Krishma Singal operates a knitting machine used to create fabric samples for a previous study. Singal recently graduated from Georgia Tech with her Ph.D. (Photo Credit: Allison Carter)","file":{"fid":"261390","name":"knittingPhysics.JPG","image_path":"\/sites\/default\/files\/2025\/07\/25\/knittingPhysics.JPG","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2025\/07\/25\/knittingPhysics.JPG","mime":"image\/jpeg","size":6205604,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2025\/07\/25\/knittingPhysics.JPG?itok=p4Akl4yz"}}},"media_ids":["677487"],"groups":[{"id":"1278","name":"College of Sciences"},{"id":"1188","name":"Research Horizons"},{"id":"126011","name":"School of Physics"}],"categories":[{"id":"194685","name":"Manufacturing"},{"id":"150","name":"Physics and Physical Sciences"},{"id":"134","name":"Student and Faculty"},{"id":"8862","name":"Student Research"}],"keywords":[{"id":"192259","name":"cos-students"},{"id":"187915","name":"go-researchnews"}],"core_research_areas":[{"id":"193653","name":"Georgia Tech Research Institute"},{"id":"39471","name":"Materials"}],"news_room_topics":[{"id":"71881","name":"Science and Technology"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EWritten by Selena Langner\u003C\/p\u003E\u003Cp\u003EContact: \u003Ca href=\u0022mailto: jess.hunt@cos.gatech.edu\u0022\u003EJess Hunt-Ralston\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}