Frustrated Smectic Liquid Crystal Elastomers as Multifunctional Mechanical Metamaterials

Frustrated Smectic Liquid Crystal Elastomers as Multifunctional Mechanical Metamaterials | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Frustrated Smectic Liquid Crystal Elastomers as Multifunctional Mechanical Metamaterials Aidan Street, Stuart Berrow, Zhenming Wang, Emily Cooper, Johan Mattsson, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8732550/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Auxetics are materials that show a negative Poisson’s ratio, i.e. thickening when under strain. The discovery of nematic liquid crystal elastomers (LCEs) as molecular auxetic materials was a paradigm-shift in the design of mechanical metamaterials as they are tuneable, transparent, scalable, non-porous and facile to fabricate. Here, we report that smectic LCEs extend known synthetic molecular auxetics to a second family. The LCEs are acrylate-based, lightly crosslinked (~8 mol%) and polymerised in the nematic phase of a precursor mixture. The resulting smectic-A LCEs exhibit correlation lengths of a few molecular lengths, suggesting layer frustration, which we confirm occurs via the mechanism predicted by de Gennes in 1979. Three of the LCEs described exhibit negative Poisson’s ratios at strains above ~0.4, thereby marking the first observation of auxetic behaviour in smectic LCEs. Shear oscillatory measurements on the LCEs demonstrate highly anisotropic moduli, which in turn enables elucidation of highly anisotropic adhesive properties, with differences as large as 20x between geometries. Furthermore, we discern that in the homeotropic case, shear moduli are comparable in both nematic and smectic A LCEs, validating theoretical expectations for such systems. Physical sciences/Chemistry/Materials chemistry/Soft materials/Liquid crystals Physical sciences/Chemistry/Polymer chemistry/Mechanical properties Physical sciences/Chemistry/Materials chemistry/Soft materials/Polymers Full Text Additional Declarations Yes there is potential Competing Interest. Stuart R. Berrow, Zhenming Wang, Helen F. Gleeson, have filed a patent related to auxetic smectic LCEs. Supplementary Files SIFrustratedSmectics.docx Supplementary Information Cite Share Download PDF Status: Under Review Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8732550","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":583074251,"identity":"7b78d26a-4ccf-4c3e-b5fb-fb4b9276f91b","order_by":0,"name":"Aidan Street","email":"","orcid":"","institution":"University of Leeds","correspondingAuthor":false,"prefix":"","firstName":"Aidan","middleName":"","lastName":"Street","suffix":""},{"id":583074250,"identity":"1d0d107e-b790-4dc4-a88c-ab3f1ec296b2","order_by":1,"name":"Stuart Berrow","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA40lEQVRIiWNgGAWjYJACZih18ACczXCAKC1sCSRr4TEgTot8A+8D5oKKe/n8EjkfDnyosLZnYD/8gJnnDG4tBgfYDZhnnCm2nDkjd8PBGWfSExt40gyYeW7g0cLAxsDM25ZgYHA7d8Nh3rbDCQwMOQzMPB/wOQyk5R9IS86Dw3//HbZn4H+DXwvDAZCWBrAWhsOMDUAkAbIFn8MOszEcnnEswUBy/jODgz3H0hPbJICMOXi8L9/exvi4oCbBgJ/n8MMHP2qs7fn5kx8+eHMMj8OY0eOAjYFgRI6CUTAKRsEoIAQArNRNt0tYM0wAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0003-3764-1613","institution":"University of Leeds","correspondingAuthor":true,"prefix":"","firstName":"Stuart","middleName":"","lastName":"Berrow","suffix":""},{"id":583074252,"identity":"5269bfe3-01be-4f2b-8166-4fffdfc30ca2","order_by":2,"name":"Zhenming Wang","email":"","orcid":"","institution":"University of Leeds","correspondingAuthor":false,"prefix":"","firstName":"Zhenming","middleName":"","lastName":"Wang","suffix":""},{"id":583074253,"identity":"cdaeec69-536e-42b5-b7cb-dd17c1428fca","order_by":3,"name":"Emily Cooper","email":"","orcid":"","institution":"University of Leeds","correspondingAuthor":false,"prefix":"","firstName":"Emily","middleName":"","lastName":"Cooper","suffix":""},{"id":583074254,"identity":"bb30b6b9-793b-409c-8fc1-b69e64a8f543","order_by":4,"name":"Johan Mattsson","email":"","orcid":"https://orcid.org/0000-0001-7057-2192","institution":"University of Leeds","correspondingAuthor":false,"prefix":"","firstName":"Johan","middleName":"","lastName":"Mattsson","suffix":""},{"id":583074255,"identity":"46c29f2b-db8d-45b7-84b2-aa62b70fe880","order_by":5,"name":"Helen Gleeson","email":"","orcid":"https://orcid.org/0000-0002-7494-2100","institution":"University of Leeds","correspondingAuthor":false,"prefix":"","firstName":"Helen","middleName":"","lastName":"Gleeson","suffix":""}],"badges":[],"createdAt":"2026-01-29 14:11:27","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8732550/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8732550/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102397626,"identity":"9b5238aa-ed04-4d13-8aa6-513eaa716cb3","added_by":"auto","created_at":"2026-02-11 10:18:35","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1077535,"visible":true,"origin":"","legend":"","description":"","filename":"FrustratedSmecticLCEMetamaterials.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8732550/v1_covered_3f7df6f4-c8f3-423f-a969-d5f260242fcb.pdf"},{"id":102037529,"identity":"62576dec-031b-435b-9aa5-469ef9f9d6ee","added_by":"auto","created_at":"2026-02-06 12:15:46","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":2343363,"visible":true,"origin":"","legend":"Supplementary Information","description":"","filename":"SIFrustratedSmectics.docx","url":"https://assets-eu.researchsquare.com/files/rs-8732550/v1/98cb8c66f3117375c57315cb.docx"}],"financialInterests":"\u003cb\u003eYes\u003c/b\u003e there is potential Competing Interest.\nStuart R. 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