Evaluation of the Corrosion of Magnets in Hydrocephalus Shunt Valve Coated in Epoxy Resin

Evaluation of the Corrosion of Magnets in Hydrocephalus Shunt Valve Coated in Epoxy Resin | 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 Evaluation of the Corrosion of Magnets in Hydrocephalus Shunt Valve Coated in Epoxy Resin Lucien Reclaru, Gabriel Buciu, Raluca Olaru (Gheorghe), Alexandru Florian Grecu, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8816922/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Graphical Abstract Abstract Hydrocephalus remains a complex neurosurgical pathology requiring permanent cerebrospinal fluid (CSF) shunting. This work explores the characteristics of polymer resins, intended to isolate and stabilize the micromagnets of the pressure and flow adjustment mechanism. The polymeric disc containing the micromagnets play a critical role in the functional stability and safety of programmable valves with magnetic mechanism: any failure of the coating can lead to corrosion phenomena and ion diffusion in the CSF. It has a diameter of 5.5 mm and on it are positioned 10 magnets with a diameter of 2 mm. However, corrosion phenomena and electrochemical interactions between the magnets and LCS represent a potential risk of ion release (Co, Sm, Nd, B) and toxicity in CFS. The study focuses on the nature of coating resins, by several techniques electrochemical using rotating electrode, by impedance (EIE), Nielsen-Tuccillo tests and cations release on encapsulated magnets. Three resins were evaluated: Stycast 1266, Stycast 1267 and Loctite( M D A). The encapsulated magnets are of CoSm and CoNd Fe B nature. All tests reveal an ion exchange permeability between electrolyte NaCl 9 g/l is the coated magnets after three days of immersion. All three resins shift the polarisation curves into the domain of 10 – 10 A/cm Degradations by corrosion phenomena on the surfaces of magnets were found in the Stycast 1266 by the Nielsen-Tuccillo test after 30 days of immersion. The extraction kinetic tests were carried out for 30, 60 and 90 days. The Stycast 1267 releases cobalt mainly in the first 60 days, at approximately 0.8 µg/l. The Loctite series a level of about 0.15 µ/l is observed for 60 days, then cobalt release increases to 1.2 µg/l after 90 days. The Stycast 1267 releases Nyodymium up to a concentration that could reach 0.6 µg.l/1. The release of Nyodymium from the Loctite series is at the detection limit < 0.2 6 g/l after 90 days. Future generations of valves, integrating electronic sensors and wireless telemetry, will have to take these constraints into account to ensure their long-term reliability and biocompatibility. Hydrocephalus Programmable shunt valve Electromagnetic valves Magnetic alloys corrosion Electrochemical evaluation Polarization curves EIS technic Nielson-Tuccillo test Cations release Toxicities Co Sm Nd magnets Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted 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-8816922","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":587972017,"identity":"d8019a29-db3b-4cb8-a328-d99baa897280","order_by":0,"name":"Lucien Reclaru","email":"","orcid":"","institution":"Scientific Independent Consultant Biomaterials and Medical Devices","correspondingAuthor":false,"prefix":"","firstName":"Lucien","middleName":"","lastName":"Reclaru","suffix":""},{"id":587972018,"identity":"6332fead-2290-4c10-a95b-7a9c55154380","order_by":1,"name":"Gabriel Buciu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABBUlEQVRIiWNgGAWjYFACHgaGBAYLBgMg8wBDBZBkPkCUFgmoljNAki0BxCKghQGqhYGxjQgt8u5nj314UCHBYC6R/PAw77w7+fxsDGzSH3MY8vlxaDE8k5c8I+GMBIPljDSDw7zbnlnObGNgkzi4jcFyZgMOLQ05xgyJbUCH3chhAGo5bGBwvwGsxcAAh+sM+98AtfyDaZkD1HKMAb8WeQmQLQ0wLQ1EaDGQeJfMkHBMgsey55nBwTnHnhlItjE2W5zdJmEgicMv8v25hxl/1NjImbMnP/7wpuaOAT8b88EbldtsDHCFGMx2HigfxGUEGS+BQwPQFjTbcbh/FIyCUTAKRjQAABzGWIieCabDAAAAAElFTkSuQmCC","orcid":"","institution":"Titu Maiorescu University Faculty of General Health Care, Targu Jiu","correspondingAuthor":true,"prefix":"","firstName":"Gabriel","middleName":"","lastName":"Buciu","suffix":""},{"id":587972019,"identity":"d7b9746c-84f8-4eba-97dc-12fbe209f06b","order_by":2,"name":"Raluca Olaru (Gheorghe)","email":"","orcid":"","institution":"University of Medicine and Pharmacy Craiova","correspondingAuthor":false,"prefix":"","firstName":"Raluca","middleName":"Olaru","lastName":"(Gheorghe)","suffix":""},{"id":587972020,"identity":"6cd805a9-4498-4d41-86c4-20110cb5f414","order_by":3,"name":"Alexandru Florian Grecu","email":"","orcid":"","institution":"University of Medicine and Pharmacy Craiova","correspondingAuthor":false,"prefix":"","firstName":"Alexandru","middleName":"Florian","lastName":"Grecu","suffix":""},{"id":587972021,"identity":"e80b8f11-b576-4634-ba7b-efb2132f9d6f","order_by":4,"name":"Ioan Dogariu","email":"","orcid":"","institution":"University of Medicine and Pharmacy Craiova","correspondingAuthor":false,"prefix":"","firstName":"Ioan","middleName":"","lastName":"Dogariu","suffix":""}],"badges":[],"createdAt":"2026-02-07 16:38:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8816922/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8816922/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102753141,"identity":"55be069e-f8d8-4919-8753-be4c31d23ffb","added_by":"auto","created_at":"2026-02-16 09:33:59","extension":"png","order_by":40,"title":"","display":"","copyAsset":false,"role":"graphical-abstract","size":66108,"visible":true,"origin":"","legend":"Hydrocephalus remains a complex neurosurgical pathology requiring permanent cerebrospinal fluid (CSF) shunting. This work explores the characteristics of polymer resins, intended to isolate and stabilize the micromagnets of the pressure and flow adjustment mechanism. The polymeric disc containing the micromagnets play a critical role in the functional stability and safety of programmable valves with magnetic mechanism: any failure of the coating can lead to corrosion phenomena and ion diffusion in the CSF. It has a diameter of 5.5 mm and on it are positioned 10 magnets with a diameter of 2 mm. However, corrosion phenomena and electrochemical interactions between the magnets and LCS represent a potential risk of ion release (Co, Sm, Nd, B) and toxicity in CFS. The study focuses on the nature of coating resins, by several techniques electrochemical using rotating electrode, by impedance (EIE), Nielsen-Tuccillo tests and cations release on encapsulated magnets. Three resins were evaluated: Stycast 1266, Stycast 1267 and Loctite( M D A). The encapsulated magnets are of CoSm and CoNd Fe B nature. All tests reveal an ion exchange permeability between electrolyte NaCl 9 g/l is the coated magnets after three days of immersion. All three resins shift the polarisation curves into the domain of 10 \u0026ndash; 10 A/cm Degradations by corrosion phenomena on the surfaces of magnets were found in the Stycast 1266 by the Nielsen-Tuccillo test after 30 days of immersion. The extraction kinetic tests were carried out for 30, 60 and 90 days. The Stycast 1267 releases cobalt mainly in the first 60 days, at approximately 0.8 \u0026micro;g/l. The Loctite series a level of about 0.15 \u0026micro;/l is observed for 60 days, then cobalt release increases to 1.2 \u0026micro;g/l after 90 days. The Stycast 1267 releases Nyodymium up to a concentration that could reach 0.6 \u0026micro;g.l/1. The release of Nyodymium from the Loctite series is at the detection limit\u0026thinsp;\u0026lt;\u0026thinsp;0.2 6 g/l after 90 days. Future generations of valves, integrating electronic sensors and wireless telemetry, will have to take these constraints into account to ensure their long-term reliability and biocompatibility.","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8816922/v1/501806eaff7c964c2bf63880.png"},{"id":102933270,"identity":"3a9faeb7-c7e4-47b9-a0e8-d01c34f84ef7","added_by":"auto","created_at":"2026-02-18 15:26:04","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1072140,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript2026.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8816922/v1_covered_1571c371-daf7-4537-96eb-1cbb9e77853e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Evaluation of the Corrosion of Magnets in Hydrocephalus Shunt Valve Coated in Epoxy Resin","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Hydrocephalus, Programmable shunt valve, Electromagnetic valves, Magnetic alloys corrosion, Electrochemical evaluation, Polarization curves, EIS technic Nielson-Tuccillo test, Cations release, Toxicities Co, Sm, Nd magnets","lastPublishedDoi":"10.21203/rs.3.rs-8816922/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8816922/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Hydrocephalus remains a complex neurosurgical pathology requiring permanent cerebrospinal fluid (CSF) shunting. This work explores the characteristics of polymer resins, intended to isolate and stabilize the micromagnets of the pressure and flow adjustment mechanism. The polymeric disc containing the micromagnets play a critical role in the functional stability and safety of programmable valves with magnetic mechanism: any failure of the coating can lead to corrosion phenomena and ion diffusion in the CSF. It has a diameter of 5.5 mm and on it are positioned 10 magnets with a diameter of 2 mm. However, corrosion phenomena and electrochemical interactions between the magnets and LCS represent a potential risk of ion release (Co, Sm, Nd, B) and toxicity in CFS. The study focuses on the nature of coating resins, by several techniques electrochemical using rotating electrode, by impedance (EIE), Nielsen-Tuccillo tests and cations release on encapsulated magnets. Three resins were evaluated: Stycast 1266, Stycast 1267 and Loctite( M D A). The encapsulated magnets are of CoSm and CoNd Fe B nature. All tests reveal an ion exchange permeability between electrolyte NaCl 9 g/l is the coated magnets after three days of immersion. All three resins shift the polarisation curves into the domain of 10 \u0026ndash; 10 A/cm Degradations by corrosion phenomena on the surfaces of magnets were found in the Stycast 1266 by the Nielsen-Tuccillo test after 30 days of immersion. The extraction kinetic tests were carried out for 30, 60 and 90 days. The Stycast 1267 releases cobalt mainly in the first 60 days, at approximately 0.8 \u0026micro;g/l. The Loctite series a level of about 0.15 \u0026micro;/l is observed for 60 days, then cobalt release increases to 1.2 \u0026micro;g/l after 90 days. The Stycast 1267 releases Nyodymium up to a concentration that could reach 0.6 \u0026micro;g.l/1. The release of Nyodymium from the Loctite series is at the detection limit\u0026thinsp;\u0026lt;\u0026thinsp;0.2 6 g/l after 90 days. Future generations of valves, integrating electronic sensors and wireless telemetry, will have to take these constraints into account to ensure their long-term reliability and biocompatibility.","manuscriptTitle":"Evaluation of the Corrosion of Magnets in Hydrocephalus Shunt Valve Coated in Epoxy Resin","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-16 09:12:48","doi":"10.21203/rs.3.rs-8816922/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ad00b078-50a3-4755-affe-6ec1c7e8264b","owner":[],"postedDate":"February 16th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-15T11:38:33+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-16 09:12:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8816922","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8816922","identity":"rs-8816922","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}