{"paper_id":"20738173-2292-4d64-bc91-443129f92ea0","body_text":"Design of a 3D printed wheelchair cushion for offloading using functionally graded materials and novel FEM topology optimization | 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 Research Article Design of a 3D printed wheelchair cushion for offloading using functionally graded materials and novel FEM topology optimization Rachel Tilley, Edmund Pickering, Maria Woodruff, David Holmes This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7483513/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 12 You are reading this latest preprint version Abstract 3D printed wheelchair cushions made from flexible thermoplastic polyurethane gyroid structures enable highly customized shape and stiffness, offering superior pressure offloading for those at risk of pressure injuries. However, techniques to optimize these cushions have not yet been developed, preventing the realisation of this potential. This work presents the first finite element model representative of the seated buttocks on a 3D printed cushion using a novel non-linear homogenization approach. A lattice optimization approach for optimising the 3-dimensional stiffness distribution across the cushion for reducing maximum contact stress is also presented. Using our approach, the optimized 3D printed cushion had a 42% reduction in maximum contact stress compared with a uniform stiffness cushion and a 31% reduction compared with a traditional contoured foam polyurethane cushion design. The deep soft tissue stress under the ischial tuberosities (sit-bones) also decreased by 39% following optimization. This model demonstrates that 3D printed cushions can benefit the millions of people who use wheelchairs, providing tangible improvements to health outcomes. The homogenization approach for representing variable stiffness gyroid structures may be used in future work to inform the design of 3D printed wheelchair cushions for clinical applications. Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 20 Nov, 2025 Reviews received at journal 18 Nov, 2025 Reviews received at journal 14 Nov, 2025 Reviews received at journal 14 Nov, 2025 Reviewers agreed at journal 04 Nov, 2025 Reviewers agreed at journal 03 Nov, 2025 Reviewers agreed at journal 18 Oct, 2025 Reviewers agreed at journal 23 Sep, 2025 Reviewers invited by journal 21 Sep, 2025 Editor assigned by journal 01 Sep, 2025 Submission checks completed at journal 01 Sep, 2025 First submitted to journal 28 Aug, 2025 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. 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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-7483513\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":522260183,\"identity\":\"bdb7da6c-e58e-41d0-bff5-b6ff8e31da25\",\"order_by\":0,\"name\":\"Rachel Tilley\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Queensland University of Technology\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Rachel\",\"middleName\":\"\",\"lastName\":\"Tilley\",\"suffix\":\"\"},{\"id\":522260185,\"identity\":\"b81368f3-8e73-4569-9c7e-0d27682dea10\",\"order_by\":1,\"name\":\"Edmund 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However, techniques to optimize these cushions have not yet been developed, preventing the realisation of this potential. This work presents the first finite element model representative of the seated buttocks on a 3D printed cushion using a novel non-linear homogenization approach. A lattice optimization approach for optimising the 3-dimensional stiffness distribution across the cushion for reducing maximum contact stress is also presented. Using our approach, the optimized 3D printed cushion had a 42% reduction in maximum contact stress compared with a uniform stiffness cushion and a 31% reduction compared with a traditional contoured foam polyurethane cushion design. The deep soft tissue stress under the ischial tuberosities (sit-bones) also decreased by 39% following optimization. This model demonstrates that 3D printed cushions can benefit the millions of people who use wheelchairs, providing tangible improvements to health outcomes. The homogenization approach for representing variable stiffness gyroid structures may be used in future work to inform the design of 3D printed wheelchair cushions for clinical applications.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Design of a 3D printed wheelchair cushion for offloading using functionally graded materials and novel FEM topology optimization\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-10-01 02:55:29\",\"doi\":\"10.21203/rs.3.rs-7483513/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"decision\",\"content\":\"Revision requested\",\"date\":\"2025-11-20T21:07:21+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2025-11-18T16:31:27+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2025-11-14T22:21:01+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2025-11-14T16:20:12+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"321537052401037988600272188568456431007\",\"date\":\"2025-11-04T08:50:34+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"11071339201492409580334944227053166282\",\"date\":\"2025-11-04T03:08:11+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"233606190034215133233587154559168617123\",\"date\":\"2025-10-19T02:30:24+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"91133042224807069324174863792058722424\",\"date\":\"2025-09-23T16:06:42+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2025-09-21T14:16:37+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2025-09-01T06:26:42+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"checksComplete\",\"content\":\"\",\"date\":\"2025-09-01T06:26:21+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"International Journal of Mechanics and Materials in Design\",\"date\":\"2025-08-28T22:32:59+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"international-journal-of-mechanics-and-materials-in-design\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"\",\"sideBox\":\"Learn more about [International Journal of Mechanics and Materials in Design](https://link.springer.com/journal/10999)\",\"snPcode\":\"10999\",\"submissionUrl\":\"https://submission.springernature.com/new-submission/10999/3\",\"title\":\"International Journal of Mechanics and Materials in Design\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"stoa\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false}}],\"origin\":\"\",\"ownerIdentity\":\"4e45cc5d-caf7-4030-a983-fcc6ad8b0389\",\"owner\":[],\"postedDate\":\"October 1st, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"under-review\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2026-02-14T02:08:41+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2025-10-01 02:55:29\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-7483513\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-7483513\",\"identity\":\"rs-7483513\",\"version\":[\"v1\"]},\"buildId\":\"8U1c8b4HqxoKbykW_rLl7\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}