Experimental study of Newtonian fluid mixing in T-shaped micromixers with variable obstacles across flow ratios

Experimental study of Newtonian fluid mixing in T-shaped micromixers with variable obstacles across flow ratios | 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 Experimental study of Newtonian fluid mixing in T-shaped micromixers with variable obstacles across flow ratios Sebastiao Peixoto, Vania Silverio This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7592758/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Mixing fluids at a microscopic scale is challenging due to flow stability, which makes mixing in microchannels a microfluidic challenge. Diffusion is slow, but passive mixing using sharp changes in flow direction and obstacles can induce convective and advective mixing that is still necessary to understand. In this study, seven T-shaped micromixers with symmetrical inlet channels and cylindrical, rectangular parallelepiped, or triangle prism obstacles in the outlet channel were fabricated using polydimethylsiloxane via soft lithography. The micromixers were tested in the laboratory, where flows were visualized under a microscope and captured using a high-frequency monochromatic camera. After digital processing of the images, the flows were characterized for Reynolds numbers Re ∈ [40, 200] and input flow ratios of 1, 2, 3, and 4. The physical phenomena influencing flow and mixing quality were analyzed to identify which factors promote effective mixing. The effects of two processes namely flow asymmetry in geometrically symmetrical inlet channels and the placement of obstacles in the outlet channel were also evaluated. It was found that, under symmetrical inlet conditions, introducing multiple obstacles in the outlet channel enhances mixing. However, for Re > 119, the mixture quality for asymmetric inlet flows decreases with the presence of obstacles in the outlet channel. microfluidics T-shaped micromixer microfabrication obstacles asymmetric flow 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-7592758","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":530682194,"identity":"dcf8e39e-5369-4b9b-a1ae-5234ffc695d2","order_by":0,"name":"Sebastiao Peixoto","email":"","orcid":"","institution":"Instituto Superior Técnico","correspondingAuthor":false,"prefix":"","firstName":"Sebastiao","middleName":"","lastName":"Peixoto","suffix":""},{"id":530682196,"identity":"3f05da03-0cda-46ee-b1d4-c2fbb137e873","order_by":1,"name":"Vania Silverio","email":"data:image/png;base64,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","orcid":"","institution":"INESC MN","correspondingAuthor":true,"prefix":"","firstName":"Vania","middleName":"","lastName":"Silverio","suffix":""}],"badges":[],"createdAt":"2025-09-11 14:08:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7592758/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7592758/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":93801802,"identity":"7f0674c8-5d03-4600-af82-8c540e25bd20","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2212656,"visible":true,"origin":"","legend":"","description":"","filename":"PeixotoandSilverio.docx","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/6c14104261d742839d4a4702.docx"},{"id":93801345,"identity":"05a5ca43-af23-4d90-8613-ae2792b31a0e","added_by":"auto","created_at":"2025-10-17 16:58:37","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":4799,"visible":true,"origin":"","legend":"","description":"","filename":"52ad6b55dee74ba0a1a47cea8d2ac8d7.json","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/65050755f1f3e4d6d96adb87.json"},{"id":93801346,"identity":"b18dc3c9-49db-4ad6-9a52-1f4cc86735e9","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":135679,"visible":true,"origin":"","legend":"","description":"","filename":"52ad6b55dee74ba0a1a47cea8d2ac8d71enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/40b398f51c31c4bef6034353.xml"},{"id":93801347,"identity":"06b13228-fb2f-4808-84d8-d45633473af2","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"jpeg","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":128056,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/e94fe1781653aba873084b9b.jpeg"},{"id":93801358,"identity":"e72792be-1e3c-40df-9d85-695b376a8253","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"jpeg","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":368642,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage10.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/fcfd7e48a44ef211a66407cf.jpeg"},{"id":93802425,"identity":"7bdf111b-cf1a-46ac-a4cc-4a41fbf5c68c","added_by":"auto","created_at":"2025-10-17 17:14:38","extension":"png","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":69860,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/e47472c2f5ebf3c9b2a06a54.png"},{"id":93802819,"identity":"a6f02d26-78ea-40cd-a1ab-99772c693a18","added_by":"auto","created_at":"2025-10-17 17:22:38","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":45698,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/533cab224650447071df25ba.png"},{"id":93801351,"identity":"56d38336-b9ab-4348-88af-d44ff0fa6612","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":107384,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/2d177b194238208ddba4a6ad.png"},{"id":93801349,"identity":"142a702f-d2bd-460c-9996-2d571ff4a817","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":49715,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage14.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/e4dc6fb0ad9ed70f3567ad44.png"},{"id":93802422,"identity":"23d5aef9-5f7d-4765-b3ab-a6d287193c42","added_by":"auto","created_at":"2025-10-17 17:14:38","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":63869,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage15.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/1d0ae34f0d93244f28495343.png"},{"id":93801803,"identity":"c925f30f-2f36-4f9a-9e99-40c4c7d43f92","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":32117,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage16.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/11872b00efbd40d31b3ef89f.png"},{"id":93801811,"identity":"05d0d6f9-0e7a-4e67-ba55-91d4bf6f083b","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"jpeg","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":392187,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage17.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/d31488fd3492640523f50350.jpeg"},{"id":93801354,"identity":"2a88234b-44e1-4745-acf0-97113fecf10f","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":39863,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage18.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/5f1fe13e8846f05a7b6a3e68.png"},{"id":93801806,"identity":"475842f5-a4cc-4c65-9d4b-1cebeb480c9f","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":58909,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage19.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/8be778b96052c0795c719925.png"},{"id":93801360,"identity":"8615fd84-8812-474e-8fa8-17ac288a201f","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"jpeg","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":363683,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/ee483565a61acc19f6a5c504.jpeg"},{"id":93801359,"identity":"cf1cc4f0-728a-414a-acdf-e85ee6aab51a","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":15361,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage20.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/90069fb5072e545ffb1e47e2.png"},{"id":93801362,"identity":"1242b1e2-95b2-4d6a-b656-6fb55cd13f83","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":55254,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage21.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/0f5669d554324137fcc83b8b.png"},{"id":93801813,"identity":"95e490b2-d920-48bd-9b6d-03a7d12050e8","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"png","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":15373,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage22.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/e7c8979b4cc33d85c9c8469f.png"},{"id":93801379,"identity":"6293c8b6-4d29-40b6-b496-b97faf9f739c","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"jpeg","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":375212,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage23.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/17dc27a7be1c3ff36feb28d9.jpeg"},{"id":93801372,"identity":"1fcaf74f-0b43-44ce-9cfb-dc66e4dc5154","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":37041,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage24.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/2fc0ca3ab1e475fa16de7e2c.png"},{"id":93801375,"identity":"add09c9f-e31b-415e-a4d5-6bf6ae25e1c2","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"jpeg","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":127705,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/14befa82f76098cdc2ee23db.jpeg"},{"id":93802427,"identity":"563c3210-6298-4ba9-a91a-6af863610b9b","added_by":"auto","created_at":"2025-10-17 17:14:38","extension":"png","order_by":21,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":278041,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/986a425de712a42d84c7e368.png"},{"id":93801374,"identity":"11f850ca-c6bc-4cc7-845c-e5b777705e11","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"jpeg","order_by":22,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":248816,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/e9c5d2e9e3a7769c0437e0c3.jpeg"},{"id":93802820,"identity":"7bc234c7-5592-4aa4-8141-9cd345a24257","added_by":"auto","created_at":"2025-10-17 17:22:38","extension":"png","order_by":23,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":23230,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/ec90e687b8b7caa27acf4067.png"},{"id":93801814,"identity":"0efe8fe0-f53c-4da4-be89-b7676cfdc80b","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"png","order_by":24,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":19380,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/5cdfa7cdbd62aba7f03c4cd2.png"},{"id":93802428,"identity":"73f37928-6b59-426f-8b59-915d403e5eae","added_by":"auto","created_at":"2025-10-17 17:14:38","extension":"jpeg","order_by":25,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":150715,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage8.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/5cc8ebafc2a34e871f47de4d.jpeg"},{"id":93801809,"identity":"0701683c-7a54-4de1-836f-380450e18ef1","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"png","order_by":26,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":65416,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/f3b53b424a195dddd0df3801.png"},{"id":93801371,"identity":"15d10715-6d00-4939-b325-74a7a6563e2a","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":27,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":35050,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/87f13863a51701494caea945.png"},{"id":93801377,"identity":"5268033a-4586-41e8-ad0a-06de2b49807c","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":28,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":407672,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/8d5da19fc58817b36673d469.png"},{"id":93801366,"identity":"ef77a034-fbac-448f-8fdf-ff7314ae5377","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":29,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":61267,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/76423a4216e0886d50508d06.png"},{"id":93801810,"identity":"1c92368d-ebef-4029-9ac7-a9e53b5b52dc","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"png","order_by":30,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7270,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/ad04f0ec068a885342b6bd40.png"},{"id":93802426,"identity":"3d8f2842-959b-4481-b13f-d5ef1a80597c","added_by":"auto","created_at":"2025-10-17 17:14:38","extension":"png","order_by":31,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":14163,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/9179ff589e930361408c0653.png"},{"id":93801383,"identity":"67326306-84b1-4b0b-b72b-3df68907eadf","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":32,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":37721,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage14.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/3ebdd9ad52c7b9b3ae0879d3.png"},{"id":93801370,"identity":"f61219be-a791-4e8a-a60c-99810dcf07af","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":33,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":51386,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage15.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/8636ee403c03b7bb15872d79.png"},{"id":93801382,"identity":"b6430ac5-c0f4-401f-9a45-dd27b4abdeae","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":34,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":30521,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage16.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/eeeb82cf467e9daf41e8d318.png"},{"id":93801387,"identity":"6b7a6324-d196-436c-a98a-a085b344a959","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":35,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":422173,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage17.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/b6039eae9371816d51df2b37.png"},{"id":93801391,"identity":"c3462d56-447b-48c7-9a74-b7c0d75e5274","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":36,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":38070,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage18.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/705adeeb976f7fc3122c18f5.png"},{"id":93802429,"identity":"f1a777bb-88ab-4e86-9e2d-b27f0da94b8e","added_by":"auto","created_at":"2025-10-17 17:14:38","extension":"png","order_by":37,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":49652,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage19.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/552cb523b38412239bb86c60.png"},{"id":93958406,"identity":"85f6ee4a-3271-470e-b89b-d4f05f574402","added_by":"auto","created_at":"2025-10-20 16:39:19","extension":"png","order_by":38,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":104548,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/11f037a8ea35e9ee0a8edca7.png"},{"id":93801373,"identity":"a0846021-5524-4db9-8205-fe5f421140ee","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":39,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":15160,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage20.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/d2db769bdd28c99b00461f60.png"},{"id":93801823,"identity":"4f26379f-16a6-4474-a09b-57f95f5981d9","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"png","order_by":40,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":44296,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage21.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/1befe8167fb29ce8d3513ea0.png"},{"id":93802822,"identity":"4e1ab31f-27e1-4f12-9a4c-156b56867bb0","added_by":"auto","created_at":"2025-10-17 17:22:38","extension":"png","order_by":41,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":15172,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage22.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/0d142ec68a76b91ed32e7066.png"},{"id":93801376,"identity":"fea7b65f-4ee5-46b4-82c8-68e91d74f019","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":42,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":458368,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage23.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/4651f685571ef8837ac81e80.png"},{"id":93801384,"identity":"68c689e6-8e5b-4029-8b4e-d9aa87cfe099","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":43,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":35570,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage24.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/55e1ab23bba29eab2a774b4c.png"},{"id":93801378,"identity":"9f76b9c9-c744-4b8f-84d4-a09c595ee799","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":44,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":61725,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/08d125486c36921ec3bf2105.png"},{"id":93801396,"identity":"524335ad-dd77-4c47-84d2-8fdb501df309","added_by":"auto","created_at":"2025-10-17 16:58:39","extension":"png","order_by":45,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":37005,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/6123a69b377dc15cc75a2403.png"},{"id":93801397,"identity":"28157a2f-3c69-45c2-9508-815918059466","added_by":"auto","created_at":"2025-10-17 16:58:39","extension":"png","order_by":46,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":225395,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/6b910fd3da96a72c2a2ed098.png"},{"id":93801819,"identity":"5333eb55-623c-409a-8c56-2237f4e4feb7","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"png","order_by":47,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":22138,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/f681d388f602eff44ef50e0e.png"},{"id":93801818,"identity":"7c0b4a9e-c972-4876-bdf4-87d819c92ddb","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"png","order_by":48,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":18442,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/c7ab45b4bb80fb5c3b5b774e.png"},{"id":93801380,"identity":"f6826f48-7b81-40a9-b599-43722768f265","added_by":"auto","created_at":"2025-10-17 16:58:38","extension":"png","order_by":49,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":25689,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/4ba367fc39a7c6c6af27a5e8.png"},{"id":93801398,"identity":"2f587824-d325-464f-b033-238a70eeb30d","added_by":"auto","created_at":"2025-10-17 16:58:39","extension":"png","order_by":50,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":56335,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/46d032e82b3a3b8525bb3508.png"},{"id":93801816,"identity":"51f11c35-4980-4f0c-8fd5-75c40ea81ec9","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"xml","order_by":51,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":135282,"visible":true,"origin":"","legend":"","description":"","filename":"52ad6b55dee74ba0a1a47cea8d2ac8d71structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/e03bed1c4da8d77acc095e5b.xml"},{"id":93801824,"identity":"22b0ccbc-810b-4a52-b3fb-fa09a66977b3","added_by":"auto","created_at":"2025-10-17 17:06:38","extension":"html","order_by":52,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":147105,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1/0f55b1580009fda38f3bca14.html"},{"id":106974235,"identity":"b5b3b0b7-8a70-4f59-a184-af580060318e","added_by":"auto","created_at":"2026-04-15 10:31:22","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":917621,"visible":true,"origin":"","legend":"","description":"","filename":"PeixotoandSilverio.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7592758/v1_covered_aa779a86-d00b-4808-aa7c-a37ee0f8ba50.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Experimental study of Newtonian fluid mixing in T-shaped micromixers with variable obstacles across flow ratios","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"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":"microfluidics, T-shaped micromixer, microfabrication, obstacles, asymmetric flow","lastPublishedDoi":"10.21203/rs.3.rs-7592758/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7592758/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMixing fluids at a microscopic scale is challenging due to flow stability, which makes mixing in microchannels a microfluidic challenge. Diffusion is slow, but passive mixing using sharp changes in flow direction and obstacles can induce convective and advective mixing that is still necessary to understand. In this study, seven T-shaped micromixers with symmetrical inlet channels and cylindrical, rectangular parallelepiped, or triangle prism obstacles in the outlet channel were fabricated using polydimethylsiloxane via soft lithography. The micromixers were tested in the laboratory, where flows were visualized under a microscope and captured using a high-frequency monochromatic camera. After digital processing of the images, the flows were characterized for Reynolds numbers Re \u0026isin; [40, 200] and input flow ratios of 1, 2, 3, and 4. The physical phenomena influencing flow and mixing quality were analyzed to identify which factors promote effective mixing. The effects of two processes namely flow asymmetry in geometrically symmetrical inlet channels and the placement of obstacles in the outlet channel were also evaluated. It was found that, under symmetrical inlet conditions, introducing multiple obstacles in the outlet channel enhances mixing. However, for Re\u0026thinsp;\u0026gt;\u0026thinsp;119, the mixture quality for asymmetric inlet flows decreases with the presence of obstacles in the outlet channel.\u003c/p\u003e","manuscriptTitle":"Experimental study of Newtonian fluid mixing in T-shaped micromixers with variable obstacles across flow ratios","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-17 16:58:33","doi":"10.21203/rs.3.rs-7592758/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":"230e95dd-b709-4e68-8207-4b72913c778c","owner":[],"postedDate":"October 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-15T10:25:23+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-17 16:58:33","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7592758","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7592758","identity":"rs-7592758","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}