{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T06:24:26Z","timestamp":1787293466674,"version":"build-2736575974"},"reference-count":19,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T00:00:00Z","timestamp":1787270400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurosci."],"abstract":"\n Introduction<\/jats:title>\n Robust, biocompatible ceramic electrical interconnects are essential for bridging the gap between macro-scale components, such as helically wound leads and connectors, and thin-film polyimide electrodes in neural interfaces. While screen-printed thick-film structures have been utilized for decades, there is a need to broaden the design space and improve reliability through thin-film techniques. This study evaluates various surface configurations to identify the optimal combination of mechanical adhesion, electrical insulation, and functional longevity.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n All samples were fabricated on 96% pure alumina (Al\n 2<\/jats:sub>\n O\n 3<\/jats:sub>\n ) substrates. Mechanical stability was evaluated via tensile shear tests, comparing thin-film platinum (Pt) with different adhesion promoters (Si\n \n x<\/jats:italic>\n <\/jats:sub>\n N\n \n y<\/jats:italic>\n <\/jats:sub>\n , SiO\n 2<\/jats:sub>\n ), laser-patterned Pt thin-films, and bare Pt thin-film against reference Al\n 2<\/jats:sub>\n O\n 3<\/jats:sub>\n substrates. Electrical insulation was assessed by performing electrochemical impedance spectroscopy and DC resistance measurements for degradation monitoring. The evaluated layer stacks with PDMS encapsulation included bare thin-film Pt, thick-film Pt\/Au with Overglaze, a SiO\n 2<\/jats:sub>\n layer, a Si\n \n x<\/jats:italic>\n <\/jats:sub>\n N\n \n y<\/jats:italic>\n <\/jats:sub>\n layer, and a layer of pulsed laser deposition (PLD) Al\n 2<\/jats:sub>\n O\n 3<\/jats:sub>\n . All samples underwent accelerated aging in phosphate buffered saline (PBS) at 60\u00b0C (acceleration factor \u223c 4.92 vs. 37\u00b0C).\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n Tensile shear strength decreased over the aging period across all groups. However, the integration of adhesion promoters increased mechanical stability compared to bare sputtered Pt, with Si\n \n x<\/jats:italic>\n <\/jats:sub>\n N\n \n y<\/jats:italic>\n <\/jats:sub>\n coating bringing adhesion levels close to the Al\n 2<\/jats:sub>\n O\n 3<\/jats:sub>\n reference samples. Electrically, Si\n \n x<\/jats:italic>\n <\/jats:sub>\n N\n \n y<\/jats:italic>\n <\/jats:sub>\n -, PLD-Al\n 2<\/jats:sub>\n O\n 3<\/jats:sub>\n , and laser-patterned samples maintained higher insulation impedances over time than PDMS on bare Pt and SiO\n 2<\/jats:sub>\n . DC resistance measurements indicate good capabilities in protecting the conductors from degradation.\n <\/jats:p>\n <\/jats:sec>\n \n Discussion<\/jats:title>\n The findings demonstrate that the addition of adhesion promoters enhances both the longevity of the mechanical bond and stability of the electrical insulation in ion-rich environments. These results provide guidance for selecting optimal ceramic interconnects for chronic peripheral-nerve implants, balancing reliability, manufacturability, and cost.<\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fnins.2026.1911095","type":"journal-article","created":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T05:37:53Z","timestamp":1787290673000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["On the reliability of non-hermetically encapsulated ceramic printed circuit boards as bridging elements in neural implants"],"prefix":"10.3389","volume":"20","author":[{"given":"Julien","family":"Martens","sequence":"first","affiliation":[{"name":"Laboratory for Biomedical Microtechnology, IMTEK, University of Freiburg","place":["Freiburg, Germany"]},{"name":"BrainLinks-BrainTools Center, IMBIT, University of Freiburg","place":["Freiburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lukas","family":"Henneken","sequence":"additional","affiliation":[{"name":"Laboratory for Biomedical Microtechnology, IMTEK, University of Freiburg","place":["Freiburg, Germany"]},{"name":"BrainLinks-BrainTools Center, IMBIT, University of Freiburg","place":["Freiburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexandra","family":"Zehr","sequence":"additional","affiliation":[{"name":"Laboratory for Biomedical Microtechnology, IMTEK, University of Freiburg","place":["Freiburg, Germany"]},{"name":"BrainLinks-BrainTools Center, IMBIT, University of Freiburg","place":["Freiburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cemre","family":"Otyakmazoglu","sequence":"additional","affiliation":[{"name":"Laboratory for Biomedical Microtechnology, IMTEK, University of Freiburg","place":["Freiburg, Germany"]},{"name":"BrainLinks-BrainTools Center, IMBIT, University of Freiburg","place":["Freiburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul","family":"\u010cvan\u010dara","sequence":"additional","affiliation":[{"name":"Laboratory for Biomedical Microtechnology, IMTEK, University of Freiburg","place":["Freiburg, Germany"]},{"name":"BrainLinks-BrainTools Center, IMBIT, University of Freiburg","place":["Freiburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas","family":"Stieglitz","sequence":"additional","affiliation":[{"name":"Laboratory for Biomedical Microtechnology, IMTEK, University of Freiburg","place":["Freiburg, Germany"]},{"name":"BrainLinks-BrainTools Center, IMBIT, University of Freiburg","place":["Freiburg, Germany"]},{"name":"Bernstein Center Freiburg, University of Freiburg","place":["Freiburg, Germany"]},{"name":"Freiburg Materials Research Center-FMF, University of Freiburg","place":["Freiburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,21]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"62","DOI":"10.1016\/j.bios.2010.05.010","article-title":"A transverse intrafascicular multichannel electrode (TIME) to interface with the peripheral nerve.","volume":"26","author":"Boretius","year":"2010","journal-title":"Biosens. 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