Download or read book Fabrication and Characterization of Silicon Microwire Neural Electrode Arrays on Flexible Substrates written by Farid Azzazy and published by . This book was released on 2014 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neuroprosthetic devices are widely employed in clinical and research settings. However, most of these devices suffer from diminishing device performance over time, likely due to the reactive tissue response of the central nervous system and scarring to biological tissue from the implantation procedure. In an effort to minimize acute tissue trauma while maintaining high spatial resolution, this thesis presents a novel miniaturized neural implant device capable of recording high-density neural signals from cortical tissue with penetrating silicon microwire sensing elements on a flexible conformable substrate. In addition to reduced tissue scarring, it is possible to improve on current commercially available neural probe designs by reducing the mechanical property mismatch between the electrode interface and neural tissue. Neural electrodes fabricated on flexible substrates have received an increase in attention in recent years; however, these designs offer moderate spatial resolution because signals are typically recorded from the surface of neural tissue in thin film style electrode designs. The MEA presented in this thesis is fabricated by a hybrid integration technology that takes advantage of both rigid penetrating pillars, similar yet smaller than commercially available technology, and is fabricated on thin film polyimide substrates. The thin film polyimide substrate allows for the electrode to make intimate contact with surrounding cortical tissue around sulci and gyri of the brain, and the silicon microwire sensing elements, which penetrate into the cortex, enable this MEA to have the potential for the best spatial resolution. The impedance of these MEAs was characterized and found to be in the range of a few hundred kilohms making them suitable for both local field potentials and single unit recordings.

Download or read book Design Fabrication and Characterization of Microelectrodes for Brain machine Interfaces written by Erin Patrick and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: The long-term goal in the design of brain-machine interfaces (BMIs) is to restore communication and control of prosthetic devices to individuals with loss of motor function due to spinal cord injuries, amyotrophic lateral sclerosis, or muscular dystrophy, for example. One of the great challenges in this effort is to develop implantable systems that are capable of processing the activity of large ensembles of cortical neurons. This work presents the design, fabrication, characterization, and in vivo testing of a neural recording platform for a pre-clinical application. The recording platform is a flexible, polyimide-based microelectrode array that can be hybrid-packaged with custom electronics in a fully-implantable form factor. Results from the microelectrode array integrated with an amplifier integrated circuit include data from in vivo neural recordings showing consistent single-unit discrimination over 42 days. Moreover, results from the electrochemical assessment of the corrosion properties of the tungsten microwire electrodes used on the microelectrode array admonish the use of tungsten in long-term implants.

Download or read book Fabrication and Characterization of Two Types of Micro electrode Arrays written by Neal Sleszynski and published by . This book was released on 1988 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fabrication and Characterization of Vertical Arrays of Ag Nanowires Grown on Silicon Substrates and Its Application as Electrode Materials in On chip Capacitors for Integrated Circuits written by Ke Xu and published by . This book was released on 2012 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fabrication and Characterization of Vertical Silicon Nanowire Arrays written by Jeffrey M. Weisse and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoelectric devices, which convert temperature gradients into electricity, have the potential to harness waste heat to improve overall energy efficiency. However, current thermoelectric devices are not cost-effective for most applications due to their low efficiencies and high material costs. To improve the overall conversion efficiency, thermoelectric materials should possess material properties that closely resemble a "phonon glass" and an "electron crystal". The desired low thermal and high electrical conductivities allow the thermoelectric device to maintain a high temperature gradient while effectively transporting current. Unfortunately, thermal transport and electrical transport are a closely coupled phenomena and it is difficult to independently engineer each specific conduction mechanism in conventional materials. One strategy to realize this is to generate nanostructured silicon (e.g. silicon nanowires (SiNWs)), which have been shown to reduce thermal conductivity ([kappa]) through enhanced phonon scattering while theoretically preserving the electronic properties; therefore, improving the overall device efficiency. The ability to suppress phonon propagation in nanostructured silicon, which has a bulk phonon mean free path ~ 300 nm at 300 K, has raised substantial interest as an ultra-low [kappa] material capable of reducing the thermal conductivity up to three orders of magnitude lower than that of bulk silicon. While the formation of porous silicon and SiNWs has individually been demonstrated as promising methods to reduce [kappa], there is a lack of research investigating the thermal conductivity in SiNWs containing porosity. We fabricated SiNW arrays using top-down etching methods (deep reactive ion etching and metal-assisted chemical etching) and by tuning the diameter with different patterning methods and tuning the internal porosity with different SiNW etching conditions. The effects of both the porosity and the SiNW dimensions at the array scale are investigated by measuring [kappa] of vertical SiNW arrays using a nanosecond time-domain thermoreflectance technique. In addition to thermoelectric devices, vertical SiNW arrays, due to their anisotropic electronic and optical properties, large surface to volume ratios, resistance to Li-ion pulverization, ability to orthogonalize light absorption and carrier transport directions, and trap light, make vertical SiNW arrays important building blocks for various applications. These may include sensors, solar cells, and Li-ion batteries. Many of these applications benefit from vertical SiNW arrays fabricated on non-silicon based substrates which endow the final devices with the properties of flexibility, transparency, and light-weight while removing any performance limitation of the silicon fabrication substrate. We then developed two vertical transfer printing methods (V-TPMs) that are used to detach SiNW arrays from their original fabrication substrates and subsequently attach them to any desired substrate while retaining their vertical alignment over a large area. The transfer of vertically aligned arrays of uniform length SiNWs is desirable to remove the electrical, thermal, optical, and structural impact from the fabrication substrate and also to enable the integration of vertical SiNWs directly into flexible and conductive substrates. Moreover, realization of a thermoelectric device requires the formation of electrical contacts on both sides of the SiNW arrays. We formed metallic contacts on both ends of the SiNW arrays with a mechanical supporting and electrical insulating polymer in between. Electrical characterization of the SiNW devices exhibited good current-voltage (I-V) characteristics independent of substrates materials and bending conditions. We believe the V-TPMs developed in this work have great potential for manufacturing practical thermoelectric devices as well as high performing, scalable SiNW array devices on flexible and conducting substrates.

Download or read book Fabrication and Characterization of Three dimensional Half cell Electrode Arrays written by George Baure (Jr.) and published by . This book was released on 2004 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The chronic challenge new vistas on long term multisite contacts to the central nervous system written by Ulrich G. Hofmann and published by Frontiers Media SA. This book was released on 2015-06-19 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Have you ever heard of a Hype-Cycle? It is a description that was put forward by an IT consultancy firm to describe certain phenomena that happen within the life cycle of new technology products. As Fenn and Raskino stated in their book (Fenn and Raskino 2008), a novel technology - a “Technology Trigger” - gives rise to a steep increase in interest, leading to the “Peak of Inflated Expectations”. Following an accumulation of more detailed knowledge on the technology and its short-comings, the stake holders may need to traverse a “Trough of Disillusionment”, which is followed by a shallower “Slope of Enlightenment”, before finally reaching the “Plateau of Productivity”. In spite of the limitations and criticisms levied on this over-simplified description of a technology’s life-cycle, it is nonetheless able to describe well the situation we are all experiencing within the brain-machine-interfacing community. Our technology trigger was the development of batch-processed multisite neuronal interfaces based on silicon during the 1980s and 1990s (Sangler and Wise 1990, Campbell, Jones et al. 1991, Wise and Najafi 1991, Rousche and Normann 1992, Nordhausen, Maynard et al. 1996). This gave rise to a seemingly exponential growth of knowledge within the neurosciences, leading to the expectation of thought-controlled devices and prostheses for handicapped people in the very near future (Chapin, Moxon et al. 1999, Wessberg, Stambaugh et al. 2000, Chapin and Moxon 2001, Serruya, Hatsopoulos et al. 2002). Unfortunately, whereas significant steps towards artificial robotic limbs could have been implemented during the last decade (Johannes, Bigelow et al. 2011, Oung, Pohl et al. 2012, Belter, Segil et al. 2013), direct invasive intracortical interfacing was not quite able to keep up with these expectations. Insofar, we are currently facing the challenging, but tedious walk through the Trough of Disillusionment. Undoubtedly, more than two decades of intense research on brain-machine-interfaces (BMI’s) have produced a tremendous wealth of information towards the ultimate goal: a clinically useful cortical prosthesis. Unfortunately even today - after huge fiscal efforts - the goal seems almost to be as far away as it was when it was originally put forward. At the very least, we have to state that one of the main challenges towards a clinical useful BMI has not been sufficiently answered yet: regarding the long term – or even truly chronic – stability of the neural cortical interface, as well as the signals it has to provide over a significant fraction of a human’s lifespan. Even the recently demonstrated advances in BMI’s in both humans and non-human primates have to deal with a severe decay of spiking activity that occurs over weeks and months (Chestek, Gilja et al. 2011, Hochberg, Bacher et al. 2012, Collinger, Kryger et al. 2014, Nuyujukian, Kao et al. 2014, Stavisky, Kao et al. 2014, Wodlinger, Downey et al. 2014) and resolve to simplified features to keep a brain-derived communication channel open (Christie, Tat et al. 2014).

Download or read book Biomedical Microsystems written by Ellis Meng and published by CRC Press. This book was released on 2011-06-22 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Poised to dramatically impact human health, biomedical microsystems (bioMEMS) technologies incorporate various aspects from materials science, biology, chemistry, physics, medicine, and engineering. Reflecting the highly interdisciplinary nature of this area, Biomedical Microsystems covers the fundamentals of miniaturization, biomaterials, microfabrication, and nanotechnology, along with relevant applications. Written by an active researcher who was recently named one of Technology Review’s Young Innovators Under 35, the book begins with an introduction to the benefits of miniaturization. It then introduces materials, fabrication technology, and the necessary components of all bioMEMS. The author also covers fundamental principles and building blocks, including microfluidic concepts, lab-on-a-chip systems, and sensing and detection methods. The final chapters explore several important applications of bioMEMS, such as microdialysis, catheter-based sensors, MEMS implants, neural probes, and tissue engineering. For readers with a limited background in MEMS and bioMEMS, this book provides a practical introduction to the technology used to make these devices, the principles that govern their operation, and examples of their application. It offers a starting point for understanding advanced topics and encourages readers to begin to formulate their own ideas about the design of novel bioMEMS. A solutions manual is available for instructors who want to convert this reference to classroom use.

Download or read book Fabrication and Characterization of Flexible and Implantable Medical Devices for Optogenetics and Neural Signal Recording written by Jeongpil Park and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis systematically studies two main topics, namely, a design and fabrication of a combined device between optoelectronics and transparent graphene-based electrodes and a development of an implantable micro-electrocorticography for a chronic implantation. The first topic introduces the design and fabrication of the flexible and implantable combined device for optogenetics area. The optoelectronics is utilized the commercial blue LED component to stimulate Channelrhodopsin-2 (ChR2) mouse model, which is a blue light-gated non-specific cation channel that neuronal activation. The micro-electrocorticography device is used the transparent graphene-based electrodes instead of the metal electrodes for recording a neural signal. Graphene that is a novel material consisting of carbon atoms, has a broad wavelength transparency from ultraviolet (UV) to infrared (IR) range. Moreover, graphene has superior properties such as electrical conductivity, mechanical flexibility, and biocompatibility etc. These advantages of graphene make it a promising material for the next generation biomedical application. Finally, we demonstrate a fully implantable system utilizing microscale LEDs vertically stacked on top of transparent graphene-based electrodes which the light can pass through, enabling synchronous a light stimulation and a neural signal recording. The second topic is on the implantable micro-electrocorticography for a chronic implantation using a 3D-printed cranial prothesis. It also allows the internal neural signal recording of the dorsal cerebral cortex of the rodent model. The photocurable polyimide (PI) substrate allows the stable mechanical property of the fabricated device. Compared to fMRI and MEG application areas, our device has a good spatial and temporal resolution. We also demonstrated the implantation method using the fabricated device and figure out the improvement in the next batch experiment. They have a potential to apply and impact the internal neural signal recording area and the neural image research field in the future.

Download or read book Fabrication and Electrical Characterization of Silicon Nanowire Arrays written by Sarah M. Dilts and published by . This book was released on 2004 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Microfabrication and Mechanical Characterization of Polymer based Microelectrode Arrays written by and published by . This book was released on 2018 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flexible microelectrode arrays (MEA's) have been in existence since early 1950 and have been widely investigated for its potential solutions for treatment of Parkinson's, Alzheimer's and other neurological disorders. Innovative designs for open-architecture and glassy carbon electrodes were designed on a platform called Coventorware. The research is focused on fabrication and mechanical characterization of polymer-based MEA for neural applications. TA Instruments Q800 dynamic mechanical analyzer is used for the rheological, thermal and multi-frequency characterization of the device. Thin traces interconnect electrode sites to bump pads region where an external PCB is mounted. The traces are insulated on both the sides by spin coating a photosensitive polymer HD4100. During the process of fabrication, the Polyimide layers undergo multiple curing cycles during which there is a substantial change in mechanical properties of the device. The device is tested to determine stiffness, yield strength and the load bearing capacity of the device. Glassy transition temperature of the micro-composite structure was determined through temperatureramp protocols. A set of multi-frequency studies were also conducted to establish a relation between applied frequency and stiffness of device. Finally, an analytical model was designed and simulated on COMSOL to correlate theoretical results with experimental results. This research will provide the basis for long term studies on favorable material properties for stable neural implants.

Download or read book Fabrication and Electrochemical Characterization of Individually addressable Submicron Band Electrode Arrays written by Milind P. Nagale and published by . This book was released on 1998 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanotechnologies in Neuroscience and Neuroengineering written by Ioan Opris and published by Frontiers Media SA. This book was released on 2020-05-05 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neuromodulation written by Elliot Krames and published by Academic Press. This book was released on 2018-01-05 with total page 1828 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neuromodulation: Comprehensive Textbook of Principles, Technologies, and Therapies, Second Edition, serves as a comprehensive and in-depth reference textbook covering all aspects of the rapidly growing field of neuromodulation. Since the publication of the first edition seven years ago, there has been an explosion of knowledge in neuromodulation, optogenetics, bioelectronics medicine and brain computer interfacing. Users will find unique discussions of the fundamental principles of neuromodulation and therapies, and how they are applied to the brain, spinal cord, peripheral nerves, autonomic nerves and various organs. The book focuses on comprehensive coverage of spinal cord stimulation, non-interventional and interventional brain stimulation, peripheral nerve stimulation, and the emerging fields of neuromodulation, including optogenetics and bioelectronics medicine. Provides a comprehensive reference that covers all aspects of the growing field of neuromodulation Written by international, leading authorities in their respective fields of neuromodulation, pain management, functional neurosurgery and biomedical engineering Includes new chapters on optogenetics, bioelectronics medicine and brain computer interfacing

Download or read book Brain Computer Interfaces written by Jonathan Wolpaw and published by Oxford University Press. This book was released on 2012-01-24 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: A recognizable surge in the field of Brain Computer Interface (BCI) research and development has emerged in the past two decades. This book is intended to provide an introduction to and summary of essentially all major aspects of BCI research and development. Its goal is to be a comprehensive, balanced, and coordinated presentation of the field's key principles, current practice, and future prospects.

Download or read book Neural Microelectrodes Design and Applications written by Stuart Cogan and published by . This book was released on 2019 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Micro Electro Mechanical Systems written by Qing-An Huang and published by Springer. This book was released on 2018-05-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook volume aims to provide a comprehensive, self-contained, and authoritative reference in MEMS. It covers the theoretical and practical aspects including but not limited to sensors, actuators, RF MEMS, micro fluids and bio MEMS systems. It is particularly recommended to undergraduates, postgraduates, researchers, scientists, and field experts. This comprehensive summary will provide a solid knowledge background and inspire innovations in this highly interdisciplinary field. The handbook series consists of 5 volumes: Micro/nano fabrication technology, MEMS, Nanomaterial, Nanomedicine and Applications of micro-/nanotechnologies in IT. Experienced researchers and experts are invited to contribute in each of these areas.The series is published under Springer Major Reference works, which allows continuous online update and publication. These features allow newcomers and other readers to keep in touch with the most up-to-date information in micro-/nanotechnologies.It presents an overview of the knowledge base, as well as selected topics and provides comprehensive and authoritative information on the field for researchers, engineers, scientists and graduate students who are involved in different aspects of micro-/nanotechnologies.This publication will provide inspiration for innovative research and application ideas for continued growth of the field.