Electrochemical Characterization of Iridium Oxide Films on Liquid Crystal Polymer for Electrical Stimulation of Neural Tissue

Electrochemical Characterization of Iridium Oxide Films on Liquid Crystal Polymer for Electrical Stimulation of Neural Tissue PDF Author: Kevin Wang
Publisher:
ISBN:
Category :
Languages : en
Pages : 176

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Electrochemical Properties of Iridium Oxide Stimulating Electrodes

Electrochemical Properties of Iridium Oxide Stimulating Electrodes PDF Author: James David Weiland
Publisher:
ISBN:
Category :
Languages : en
Pages : 290

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Proceedings of the Symposium on Surface Oxide Films

Proceedings of the Symposium on Surface Oxide Films PDF Author: Jennifer A. Bardwell
Publisher: The Electrochemical Society
ISBN: 9781566771689
Category : Science
Languages : en
Pages : 338

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Iridium Oxide-carbon Hybrid Materials as Electrodes for Neural Systems

Iridium Oxide-carbon Hybrid Materials as Electrodes for Neural Systems PDF Author: Nina Magali Carretero González
Publisher:
ISBN: 9788449045011
Category :
Languages : en
Pages : 264

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El desarrollo de interfaces neuronales requiere el uso de nuevos materiales electroactivos y biocompatibles, que al aplicar campos eléctricos no causen efectos secundarios que pueden dañar los tejidos o degradar la funcionalidad del electrodo. A día de hoy, existen diferentes materiales electroactivos que se usan como electrodos en el sistema nervioso: oro, platino, carbón, Pt-Ir o IrOx entre otros, siendo este último el que ha mostrado superiores resultados. Una alta eficiencia electroquímica, estabilidad en condiciones biológicas y biocompatibilidad, han hecho del IrOx el material más prometedor como electrodo para estimulación y registro de señales neuronales. Sin embargo, los avances tecnológicos han generado una demanda de nuevos materiales con propiedades mejoradas y con menos inconvenientes que los actuales (bajos valores de capacidad de carga o la rigidez inherente de este tipo de óxidos, ya que presentan poca compatibilidad con los tejidos blandos). Estas mejoras se pueden conseguir con el uso de materiales híbridos, que unan las diferentes propiedades de los componentes. En este sentido, se han preparado electroquímicamente híbridos IrOx-CNTs, con propiedades mejoradas tras la adicción de nanotubos de carbono. La composición química de estos híbridos es muy parecida a la obtenida para IrOx, aunque la incorporación de nanotubos de carbono hace la superficie más rugosa, aumentando de esta manera el área superficial del material. Estas propiedades, junto con el aumento de la conductividad proporcionada por los nanotubos de carbono, tienen como consecuencia elevados valores de capacidad de carga electroquímica. También, la estabilidad de las capas resultantes mejora en comparación con las muestras de IrOx. Las pruebas de biocompatibilidad realizadas a las muestras IrOx-CNTs han mostrado una alta supervivencia y funcionalidad neural, parecida a la obtenida con IrOx o borosilicato (usado como referencia). Estos datos, validan este tipo de nuevos materiales como prometedores electrodos neurales. También se han preparado híbridos de IrOx con grafito y grafeno. En ambas capas, se ha observado la presencia de partículas de carbón, aunque la presencia de grafeno de única lámina no ha podido ser confirmada, y serán necesarios más experimentos. Las propiedades electroquímicas de estos híbridos, IrOx-grafito e IrOx-grafeno, son similares a las obtenidas para IrOx-CNTs, pero con mayores valores de capacidad de carga. Sin embargo, la estabilidad electroquímica es pobre para el híbrido de grafito, y finalmente la capa se despega, debido presuntamente, a la estructura heterogénea de los híbridos de grafito, en la cual, grandes partículas de carbón no están completamente introducidas en la matriz del IrOx. Híbridos de IrOx con grafeno dopado con nitrógeno se han preparado también, mostrando buenas propiedades y altos valores de capacidad de carga y estabilidad, incluso comparados con los resultados obtenidos para los híbridos con grafeno no dopado. El aumento de la conductividad en estos materiales se puede deber a la presencia de nitrógeno, que induce el aumento de defectos en las láminas de grafeno. La biocompatibilidad de estos materiales híbridos grafíticos está siendo estudiada. Tri-híbridos poliméricos también han sido sintetizados electroquímicamente, IrOx-PEDOT-CNTs. El uso de una matríz polimérica, ofrece más flexibilidad al futuro electrodo, lo que es deseable para aplicaciones en tejidos blandos. Sin embargo, los primeros resultados obtenidos muestran que el polímero encapsula los nanotubos de carbono y el IrOx, minimizando sus propiedades electroquímicas. Como consecuencia, la conducta electroquímica del material híbrido es muy similar a la obtenida en otros polímeros, como PEDOT-PSS. Las pruebas de biocompatibilidad para estos híbridos poliméricos muestran baja viabilidad neuronal, aunque un nuevo modelo de co-cultivos (astrocitos-neuronas) se ha propuesto para mejorar la biocompatibilidad en este tipo de materiales. Los materiales obtenidos en todos los casos, son capas bien adheridas, lo que permite su futuro uso como electrodos o substratos de crecimiento neuronal.

Electrochemical Characteristics of Anodic and Sputtered Iridium Oxide Films

Electrochemical Characteristics of Anodic and Sputtered Iridium Oxide Films PDF Author: Stanley M. F. Yuen
Publisher:
ISBN:
Category :
Languages : en
Pages : 110

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Cumulated Index Medicus

Cumulated Index Medicus PDF Author:
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 1844

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Iridium Oxide (IrO2) as a Top Electrode for Ferroelectric Micro-Electro-Mechanical Systems (MEMS) Devices for Radiation Rich Environments

Iridium Oxide (IrO2) as a Top Electrode for Ferroelectric Micro-Electro-Mechanical Systems (MEMS) Devices for Radiation Rich Environments PDF Author: Manuel Rivas
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 124

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The multifunctional properties of ferroelectric materials make them ideal components for numerous applications including for extreme environments such as space. Iridium oxide (IrO2) electrodes have been demonstrated to improve the lifetime of ferroelectric memory devices, however little is known about its influence on the electromechanical properties important for ferroelectric microelectromechanical systems (MEMS). The performance of thin film lead zirconate titanate (PZT) based MEMS is affected by the processing conditions, composition, device design, electrode materials, and the environment. This work details the development and characterization of iridium oxide electrodes for PZT based microelectromechanical and pyroelectric-harvesting systems, fabrication induced defects, and design of clamped vs unclamped devices. This work also considers the influence of iridium oxide top electrodes on the properties of PZT films and MEMS devices subjected to gamma and heavy ion radiation for applications in space and for evaluating nuclear material where human exposure must be kept to a minimum. Using single point force measurements with an atomic force microscope, this work presents the first known experimental value of Young's modulus for thin film IrO2 (????????2 = 262 GPa). It was discovered that iridium oxide films of different morphologies are produced by manipulating the reactive gas flow rate in a sputtering process. Planar IrO2 for piezoelectric applications was optimized at 60 sccm O2 flow rate deposited at 500°C. Nanostructured, 2D platelets are observed for high oxygen flow rates (100 sccm) producing a self-limiting dense columnar film as the base of the plate-like structures. While the plate-like region continues to grow with increased deposition at a rate of ~6 nm/s, the dense film appears to reach a critical thickness of approximately 60 ± 10. Devices with iridium oxide top electrode appear to be more radiation resistant when compared to identically fabricated devices with a platinum (Pt) top electrode, when exposed up to 10 Mrad(Si) of gamma rays from a 60Co source and an equivalent dose with Fe3+ ions.

Handbook of Neuroengineering

Handbook of Neuroengineering PDF Author: Nitish V. Thakor
Publisher: Springer Nature
ISBN: 9811655405
Category : Technology & Engineering
Languages : en
Pages : 3686

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Book Description
This Handbook serves as an authoritative reference book in the field of Neuroengineering. Neuroengineering is a very exciting field that is rapidly getting established as core subject matter for research and education. The Neuroengineering field has also produced an impressive array of industry products and clinical applications. It also serves as a reference book for graduate students, research scholars and teachers. Selected sections or a compendium of chapters may be used as “reference book” for a one or two semester graduate course in Biomedical Engineering. Some academicians will construct a “textbook” out of selected sections or chapters. The Handbook is also meant as a state-of-the-art volume for researchers. Due to its comprehensive coverage, researchers in one field covered by a certain section of the Handbook would find other sections valuable sources of cross-reference for information and fertilization of interdisciplinary ideas. Industry researchers as well as clinicians using neurotechnologies will find the Handbook a single source for foundation and state-of-the-art applications in the field of Neuroengineering. Regulatory agencies, entrepreneurs, investors and legal experts can use the Handbook as a reference for their professional work as well.​

Bioelectronic Medicine

Bioelectronic Medicine PDF Author: Valentin A. Pavlov
Publisher: Perspectives Cshl
ISBN: 9781621823025
Category : Medical
Languages : en
Pages : 350

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Book Description
"Cold Spring Harbor perspectives in medicine."

Neural Microelectrodes: Design and Applications

Neural Microelectrodes: Design and Applications PDF Author: Stuart Cogan
Publisher:
ISBN: 9783039213207
Category : Electronic books
Languages : en
Pages : 1

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Book Description
Neural electrodes enable the recording and stimulation of bioelectrical activity in the nervous system. This technology provides neuroscientists with the means to probe the functionality of neural circuitry in both health and disease. In addition, neural electrodes can deliver therapeutic stimulation for the relief of debilitating symptoms associated with neurological disorders such as Parkinson's disease and may serve as the basis for the restoration of sensory perception through peripheral nerve and brain regions after disease or injury. Lastly, microscale neural electrodes recording signals associated with volitional movement in paralyzed individuals can be decoded for controlling external devices and prosthetic limbs or driving the stimulation of paralyzed muscles for functional movements. In spite of the promise of neural electrodes for a range of applications, chronic performance remains a goal for long-term basic science studies, as well as clinical applications. New perspectives and opportunities from fields including tissue biomechanics, materials science, and biological mechanisms of inflammation and neurodegeneration are critical to advances in neural electrode technology. This Special Issue will address the state-of-the-art knowledge and emerging opportunities for the development and demonstration of advanced neural electrodes.