| 1. |
- Bernardin, Evans, et al.
(författare)
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Development of an all-SiC neuronal interface device
- 2016
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Ingår i: MRS Advances. - : Cambridge University Press. - 2059-8521. ; 1:55, s. 3679-3684
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Tidskriftsartikel (refereegranskat)abstract
- The intracortical neural interface (INI) is a key component of brain machine interfaces (BMI) which offer the possibility to restore functions lost by patients due to severe trauma to the central or peripheral nervous system. Unfortunately today’s neural electrodes suffer from a variety of design flaws, mainly the use of non-biocompatible materials based on Si or W with polymer coatings to mask the underlying material. Silicon carbide (SiC) is a semiconductor that has been proven to be highly biocompatible, and this chemically inert, physically robust material system may provide the longevity and reliability needed for the INI community. The design, fabrication, and preliminary testing of a prototype all-SiC planar microelectrode array based on 4H-SiC with an amorphous silicon carbide (a-SiC) insulator is described. The fabrication of the planar microelectrode was performed utilizing a series of conventional micromachining steps. Preliminary data is presented which shows a proof of concept for an all-SiC microelectrode device.
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| 2. |
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| 3. |
- Bernardin, Evans K., et al.
(författare)
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Demonstration of a Robust All-Silicon-Carbide Intracortical Neural Interface
- 2018
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Ingår i: Micromachines. - : MDPI. - 2072-666X. ; 9:8
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Tidskriftsartikel (refereegranskat)abstract
- Intracortical neural interfaces (INI) have made impressive progress in recent years but still display questionable long-term reliability. Here, we report on the development and characterization of highly resilient monolithic silicon carbide (SiC) neural devices. SiC is a physically robust, biocompatible, and chemically inert semiconductor. The device support was micromachined from p-type SiC with conductors created from n-type SiC, simultaneously providing electrical isolation through the resulting p-n junction. Electrodes possessed geometric surface area (GSA) varying from 496 to 500 K m(2). Electrical characterization showed high-performance p-n diode behavior, with typical turn-on voltages of 2.3 V and reverse bias leakage below 1 nArms. Current leakage between adjacent electrodes was 7.5 nArms over a voltage range of -50 V to 50 V. The devices interacted electrochemically with a purely capacitive relationship at frequencies less than 10 kHz. Electrode impedance ranged from 675 +/- 130 k (GSA = 496 mu m(2)) to 46.5 +/- 4.80 k (GSA = 500 K mu m(2)). Since the all-SiC devices rely on the integration of only robust and highly compatible SiC material, they offer a promising solution to probe delamination and biological rejection associated with the use of multiple materials used in many current INI devices.
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| 4. |
- Coletti, Camilla, et al.
(författare)
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Surface morphology and structure of hydrogen etched 3C-SiC(001) on Si(001)
- 2006
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Ingår i: Silicon Carbide 2006 - Materials, Processing and Devices. - : Materials Research Society. ; , s. 131-136
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The surface of 3C-SiC(001) single-crystal epilayers grown on Si(001) substrates is well known to be inhomogeneous and defective. Therefore, the control and understanding at the atomic scale of 3C-SiC surfaces is a key issue. We study the effect of hydrogen etching at different temperatures on the morphology of 3C-SiC(001) surfaces by using Nomarksi optical microscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). As-grown 3C-SiC(001) samples have been hydrogen etched in a horizontal hot-wall chemical vapor deposition (CVD) reactor at atmospheric pressure for different times and temperatures. Flat, high-quality surfaces presenting defined atomic terraces were observed within the 3C-SiC grain boundaries after etching at 1200°C for 30 minutes. Higher etching temperatures resulted in surfaces with step bunching and enlarged surface defects. Samples etched under the best conditions have been studied using low-energy electron diffraction (LEED) and Auger electron spectroscopy (AES).
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| 5. |
- Frewin, Christopher L., et al.
(författare)
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Silicon Carbide As a Robust Neural Interface (Invited)
- 2016
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Ingår i: GALLIUM NITRIDE AND SILICON CARBIDE POWER TECHNOLOGIES 6. - : ELECTROCHEMICAL SOC INC. - 9781607687290 ; , s. 39-45
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Konferensbidrag (refereegranskat)abstract
- The intracortical neural interface (INI) could be a key component of brain machine interfaces (BMI), devices which offer the possibility of restored physiological neurological functionality for patients suffering from severe trauma to the central or peripheral nervous system. Unfortunately the main components of the INI, microelectrodes, have not shown appropriate long-term reliability due to multiple biological, material, and mechanical issues. Silicon carbide (SiC) is a semiconductor that is completely chemically inert within the physiological environment and can be micromachined using the same methods as with Si microdevices. We are proposing that a SiC material system may provide the improved longevity and reliability for INI devices. The design, fabrication, and preliminary electrical and electrochemical testing of an all-SiC prototype microelectrode array based on 4H-SiC, with an amorphous silicon carbide (a-SiC) insulator, is described. The fabrication of the planar microelectrode was performed utilizing a series of conventional micromachining steps. Preliminary electrochemical data are presented which show that these prototype electrodes display suitable performance.
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| 6. |
- Soubatch, Serguei, et al.
(författare)
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Atomic Structure of Non-Basal-Plane SiC Surfaces : Hydrogen Etching and Surface Phase Transformations
- 2006
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Ingår i: Silicon Carbide 2006 - Materials, Processing and Devices. - : Materials Research Society. - 1558998675 ; , s. 271-282
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A-plane (11-20) and diagonal cut (1-102) and (-110-2) surfaces of 4H-SiC have been investigated using atomic force microscopy (AFM), low-energy electron diffraction (LEED), Auger electron spectroscopy (AES), X-ray photoemission spectroscopy (XPS) and scanning tunneling microscopy (STM). After hydrogen etching the surfaces show large, flat terraces. On SiC(11-20) steps down to single atomic heights are observed. On the diagonal cut surfaces steps run parallel and perpendicular to the [-1101] direction, yet drastically different morphologies for the two isomorphic orientations are found. All surfaces immediately display a sharp LEED pattern. For SiC(1-102) and SiC(-110-2) the additional significant presence of oxygen in the AES spectra indicates the development of an ordered oxide. All three surfaces show an oxygen free, well ordered surface after Si deposition and annealing. A transformation between different surface phases is observed upon annealing.
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