{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,25]],"date-time":"2026-10-25T02:53:22Z","timestamp":1792896802946,"version":"4.5.0"},"reference-count":27,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T00:00:00Z","timestamp":1770336000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Science and Technology Innovation Talent Project on Manufacturing Industry of Harbin","award":["2023HBRCGD011"],"award-info":[{"award-number":["2023HBRCGD011"]}]},{"name":"Key Research and Development Plan Project of Heilongjiang Province","award":["2022ZX02C22"],"award-info":[{"award-number":["2022ZX02C22"]}]},{"DOI":"10.13039\/501100005230","name":"Natural Science Foundation of Chongqing, China","doi-asserted-by":"publisher","award":["CSTB2023NSCQ-MSX0822"],"award-info":[{"award-number":["CSTB2023NSCQ-MSX0822"]}],"id":[{"id":"10.13039\/501100005230","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gels"],"abstract":"<jats:p>High-resolution biofabrication requires precise microscale deposition, yet drop-on-demand (DOD) inkjet bioprinting is constrained by a narrow printable viscosity window. Many biocompatible hydrogel precursors display high zero-shear viscosity and strong shear-thinning, so stable droplet ejection typically requires dilution or reformulation that can compromise the biochemical microenvironment. We present a transient shear-enabled jetting method that exploits intrinsic shear-thinning by using a high-frequency electromagnetic microvalve to deliver short, high-pressure pulses. The resulting localized shear dynamically lowers apparent viscosity in the nozzle region and promotes controlled nucleation, ligament formation, necking, and pinch-off. A coupled, rheology-informed modeling framework (axisymmetric transient CFD, valve dynamics, and electromagnetic FEM) links actuation parameters to droplet volume and stability and guides hardware optimization. Experiments with 2.5% (w\/v) sodium alginate validate stable droplet generation and tunable droplet size via stroke length and driving conditions. These results define a practical process window for high-resolution droplet printing of high-viscosity shear-thinning hydrogel inks.<\/jats:p>","DOI":"10.3390\/gels12020148","type":"journal-article","created":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T10:05:47Z","timestamp":1770372347000},"page":"148","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Mechanistic Investigation of Microdroplet Formation in High-Viscosity Shear-Thinning Hydrogel Bioinks"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8751-5626","authenticated-orcid":false,"given":"Qiang","family":"Gao","sequence":"first","affiliation":[{"name":"School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanling","family":"Mi","sequence":"additional","affiliation":[{"name":"School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaicheng","family":"Yu","sequence":"additional","affiliation":[{"name":"School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5031-7434","authenticated-orcid":false,"given":"Youyun","family":"Shang","sequence":"additional","affiliation":[{"name":"School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0492-5321","authenticated-orcid":false,"given":"Lihua","family":"Lu","sequence":"additional","affiliation":[{"name":"School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongqiang","family":"Gao","sequence":"additional","affiliation":[{"name":"School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peng","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2525","DOI":"10.1038\/sj.jid.5700865","article-title":"Tight junctions\/adherens junctions: Basic structure and function","volume":"127","author":"Niessen","year":"2007","journal-title":"J. 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