Optimizing the fabrication of a 3D high-resolution implant for neural stimulation

Journal of Biological Engineering

Methodology

Doron Gerber¹  Amos Markus²  Erel Lasnoy²  Nairouz Farah²  Yoav Chemla²  Tamar Azrad Leibovitch²  Yossi Mandel³  Zeev Zalevsky⁴  Gal Shpun⁵ 

[1] Bar Ilan Institute for Nanotechnology & Advanced Materials (BINA), Bar Ilan University, 5290002, Ramat Gan, Israel;Faculty of Life Sciences, School of Optometry & Visual Science, Bar Ilan University, 5290002, Ramat Gan, Israel;Bar Ilan Institute for Nanotechnology & Advanced Materials (BINA), Bar Ilan University, 5290002, Ramat Gan, Israel;Faculty of Life Sciences, School of Optometry & Visual Science, Bar Ilan University, 5290002, Ramat Gan, Israel;Bar Ilan Institute for Nanotechnology & Advanced Materials (BINA), Bar Ilan University, 5290002, Ramat Gan, Israel;The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel;The Alexander Kofkin Faculty of Engineering, Bar Ilan University, 5290002, Ramat Gan, Israel;Bar Ilan Institute for Nanotechnology & Advanced Materials (BINA), Bar Ilan University, 5290002, Ramat Gan, Israel;The Alexander Kofkin Faculty of Engineering, Bar Ilan University, 5290002, Ramat Gan, Israel;Faculty of Life Sciences, School of Optometry & Visual Science, Bar Ilan University, 5290002, Ramat Gan, Israel;Bar Ilan Institute for Nanotechnology & Advanced Materials (BINA), Bar Ilan University, 5290002, Ramat Gan, Israel;

关键词: Neural interfaces;    Retinal prostheses;    Implantable devices;    Electrical Neuro-stimulation;    SU-8 Photolithography;    Bio-MEMS;   

DOI  :  10.1186/s13036-023-00370-8

 received in 2022-09-12, accepted in 2023-07-24,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundTissue-integrated micro-electronic devices for neural stimulation hold great potential in restoring the functionality of degenerated organs, specifically, retinal prostheses, which are aimed at vision restoration. The fabrication process of 3D polymer-metal devices with high resolution and a high aspect-ratio (AR) is very complex and faces many challenges that impair its functionality.ApproachHere we describe the optimization of the fabrication process of a bio-functionalized 3D high-resolution 1mm circular subretinal implant composed of SU-8 polymer integrated with dense gold microelectrodes (23μm pitch) passivated with 3D micro-well-like structures (20μm diameter, 3μm resolution). The main challenges were overcome by step-by-step planning and optimization while utilizing a two-step bi-layer lift-off process; bio-functionalization was carried out by N2 plasma treatment and the addition of a bio-adhesion molecule.Main resultsIn-vitro and in-vivo investigations, including SEM and FIB cross section examinations, revealed a good structural design, as well as a good long-term integration of the device in the rat sub-retinal space and cell migration into the wells. Moreover, the feasibility of subretinal neural stimulation using the fabricated device was demonstrated in-vitro by electrical activation of rat’s retina.ConclusionsThe reported process and optimization steps described here in detail can aid in designing and fabricating retinal prosthetic devices or similar neural implants.

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

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