A5090339105- Neuroscience and Neural Engineering
- EEG and Brain-Computer Interfaces
- Muscle activation and electromyography studies
- Advanced Memory and Neural Computing
- Diamond and Carbon-based Materials Research
- Neurological disorders and treatments
- Conducting polymers and applications
- Photoreceptor and optogenetics research
- Neural Networks and Applications
- Metal and Thin Film Mechanics
- Semiconductor materials and devices
University of Oregon
2024
The University of Texas at Dallas
2017-2018
Foreign body response to indwelling cortical microelectrodes limits the reliability of neural stimulation and recording, particularly for extended chronic applications in behaving animals. The extent which this compromises stability devices depends on many factors including materials used electrode construction, size, geometry structure. Here, we report development microelectrode arrays (MEAs) based amorphous silicon carbide (a-SiC).This technology utilizes a-SiC its employs semiconductor...
Objective. Most preparations for making neural recordings degrade over time and eventually fail due to insertion trauma reactive tissue response. The magnitudes of these responses are thought be related the electrode size (specifically, cross-sectional area), relative stiffness electrode, degree tolerance material. Flexible carbon fiber ultra-microelectrodes have a much smaller cross-section than traditional electrodes low reactivity, thus may enable improved longevity in central peripheral...
Host encapsulation decreases the ability of chronically implanted microelectrodes to record or stimulate neural activity. The degree foreign body response is thought depend strongly on cross-sectional dimensions electrode shaft penetrating tissue. Microelectrodes with cellular sub-cellular scale dimensions, such as carbon fiber ultramicroelectrodes have been previously demonstrated elicit minimal tissue response, but their small geometric surface area results in high impedances for...
Here, we report on chronic in-vivo testing of a 16-channel wireless floating microelectrode array (WFMA) in rat sciatic nerve model. Muscle threshold currents, charge injection levels, and density were monitored for electrodes two WFMA devices implanted into animal subjects over five month period. This type stimulation device could eliminate problems associated with percutaneous connectors variety neural prostheses other medical devices.
Microelectrode arrays that consistently and reliably record stimulate neural activity under conditions of chronic implantation have so far eluded the interface community due to failures attributed both biotic abiotic mechanisms. Arrays with transverse dimensions 10 µm or below are thought minimize inflammatory response; however, reduction implant thickness also decreases buckling thresholds for materials low Young’s modulus. While these issues been overcome using stiffer, thicker as...
Abstract The change in residual stress plasma enhanced chemical vapor deposition amorphous silicon carbide (a‐SiC:H) films exposed to air and wet ambient environments is investigated. A close relationship between condition identified from mechanical characterization of a‐SiC:H films. Evidence reacting with oxygen water the environment are presented. effect parameters on oxidation variation film studied. It found that deposited at low temperature or power susceptible undergo a notable...
Size and material considerations are important in the development of next-generation chronically reliable neural interface devices. In this review, we discuss use amorphous silicon carbide (a-SiC) for fabrication indwelling electrode arrays with ultrathin penetrating shanks stimulation recording. The a-SiC film is stable saline environments has a high intrinsic stiffness that allows tissue-penetrating extremely small cross-sectional areas (<60 μm2). Present literature on and/or...
Functional stability and in-vivo reliability are significant factors determining the longevity of a neural interface. In this ongoing study, we test performance wireless floating microelectrode array (WFMA) over period 143 days. The topography microelectrodes has allowed for selective stimulation different fascicles rat sciatic nerve. We confirmed that motor evoked thresholds remain stable time nerve charges were within tissue safety limits. Importantly, responses elicited at threshold...
The intracortical neural interface (INI) could be a key component of brain machine interfaces (BMI), devices which offer the possibility restored physiological neurological functionality for patients suffering from severe trauma to central or peripheral nervous system. Unfortunately main components INI, microelectrodes, have not shown appropriate long-term reliability due multiple biological, material, and mechanical issues. Silicon carbide (SiC) is semiconductor that completely chemically...
Abstract Objective. Kilohertz (kHz) frequency stimulation has gained attention as a neuromodulation therapy in spinal cord and peripheral nerve block applications, mainly for treating chronic pain. Yet, few studies have investigated the effects of high-frequency on performance electrode materials. In this work, we assess electrochemical characteristics stability sputtered iridium oxide film (SIROF) microelectrodes under kHz pulsed electrical stimulation. Approach. SIROF were subjected to...
Abstract Most preparations for making neural recordings degrade over time and eventually fail due to insertion trauma reactive tissue response. The magnitudes of these responses are thought be related the electrode size (specifically, cross-sectional area) relative stiffness material. Carbon fiber ultramicroelectrodes have a much smaller cross-section than traditional electrodes thus may enable improved longevity in central peripheral nervous systems. Only two carbon array designs been...
The potential impact of neuro-compatible implantable devices to assist millions who suffer from brain and spinal cord injury or limb loss is tremendous, both in restoring patient health, as well quality life. Until now, no known reliable solution this challenge has been found, with most the current technology relying on non-neuro-compatible materials such silicon, tungsten, platinum, polymer insulators. Silicon Carbide (SiC) and, particular 3C-SiC, appears be an ideal material meet...