Stability of Thin-Film Metallization in Flexible Stimulation Electrodes: Analysis and Improvement of in vivo Performance
| Autor: | Giuseppe Granata, Victor Lopezalvarez, Jean-Louis Divoux, Pawel Maciejasz, Ken Yoshida, Francesco Maria Petrini, Stanisa Raspopovic, David Guiraud, Winnie Jensen, Tim Boretius, Paolo Maria Rossini, Thomas Stieglitz, David Andreu, Paul Čvančara, Xavier Navarro, Eduardo Fernandez, Silvestro Micera |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
0206 medical engineering Delamination 02 engineering and technology Adhesion Substrate (electronics) 021001 nanoscience & nanotechnology 020601 biomedical engineering chemistry.chemical_compound chemistry Electrode Silicon carbide Thin film 0210 nano-technology Layer (electronics) Polyimide Biomedical engineering |
| DOI: | 10.1101/644914 |
| Popis: | Micro-fabricated neural interfaces based on polyimide (PI) are achieving increasing importance in translational research. The ability to produce well-defined micro-structures with properties that include chemical inertness, mechanical flexibility and low water uptake are key advantages for these devices. This paper reports the development of the transverse intrafascicular multichannel electrode (TIME) used to deliver intraneural sensory feedback to an upper-limb amputee in combination with a sensorized hand prosthesis. A first-in-human study limited to 30 days was performed. About 90 % of the stimulation contact sites of the TIMEs maintained electrical functionality and stability during the full implant period. However, optical analysis post-explantation revealed that 62.5 % of the stimulation contacts showed signs of mechanical damage at the metallization-PI interface. Such damage likely occurred due to handling during explantation and subsequent analysis, since a significant change in impedance was not observed in vivo. Nevertheless, whereas device integrity is mandatory for long-term functionality in chronic implantation, measures to increase the bonding strength of the metallization-PI interface deserve further investigation. We report here that silicon carbide (SiC) is an effective adhesion-promoting layer resisting heavy electrical stimulation conditions in vivo. Optical analysis of the new electrodes revealed that the metallization remained unaltered after delivering over 14 million pulses in vivo without signs of delamination at the metallization-PI interface. Reliable adhesion of thin-film metallization to substrate has been proven using SiC, improving the potential transfer of micro-fabricated neural electrodes for chronic clinical applications. |
| Databáze: | OpenAIRE |
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