A5050780244- Neuroscience and Neural Engineering
- EEG and Brain-Computer Interfaces
- Advanced Memory and Neural Computing
- Photoreceptor and optogenetics research
- Vagus Nerve Stimulation Research
- Analytical Chemistry and Sensors
- Gas Sensing Nanomaterials and Sensors
- Neural dynamics and brain function
- Semiconductor materials and devices
- Conducting polymers and applications
- Advanced Sensor and Energy Harvesting Materials
- Chalcogenide Semiconductor Thin Films
- ZnO doping and properties
- Muscle activation and electromyography studies
- Copper-based nanomaterials and applications
- Transition Metal Oxide Nanomaterials
- Molecular Communication and Nanonetworks
- Semiconductor Quantum Structures and Devices
- Quantum Dots Synthesis And Properties
- Hydrogels: synthesis, properties, applications
- Electronic and Structural Properties of Oxides
- Electrochemical sensors and biosensors
- Hearing Loss and Rehabilitation
- Microfluidic and Capillary Electrophoresis Applications
- Heart Rate Variability and Autonomic Control
West Virginia University
2021-2025
Feinstein Institute for Medical Research
2018-2024
University of Utah
2011-2022
Northwell Health
2018-2021
Hofstra University
2020-2021
Blackrock Microsystems (United States)
2017
University of Florida
1999-2003
Electronic neural interfaces have been developed to restore function the nervous system for patients with disorders. A conformal and chronically stable dielectric encapsulation is required protect interface device from harsh physiological environment localize active electrode tips. Chemical vapor deposited Parylene-C films were studied as a potential implantable material using impedance spectroscopy leakage current measurements. Both tests performed in 37degC saline solution, showed that...
Neural interfaces connect signal processing electronics to the nervous system via implanted microelectrode arrays such as Utah electrode array (UEA). The active sites of UEA are coated with thin films either platinum (Pt) or iridium oxide (IrOx). Pt and IrOx have attracted attention a stimulating recording material due their ability transfer between ionic electronic current resist corrosion. physical, mechanical, chemical, electrical optical properties depend on method deposition parameters...
Objective. Among the currently available neural interface devices, there has been a need for penetrating electrode array with high electrode-count and electrode-density (the number of electrodes/mm2) that can be used electrophysiological studies sub-millimeter neuroanatomical structures. We have developed such microelectrode both (25 (up to 96 electrodes) small nervous system structures, based on existing Utah Slanted Electrode Array (USEA). Such arrays are expected provide greater access...
Objective-We focus on improving the long-term stability and functionality of neural interfaces for chronic implantation by using bilayer encapsulation.Approach-We evaluated reliability Utah electrode array (UEA) based encapsulated 52 nm atomic layer deposited (ALD) Al 2 O 3 6 μm Parylene C bilayer, compared these to devices with baseline Parylene-only encapsulation.Three variants arrays including wired, wireless, active UEAs were used evaluate this encapsulation scheme, immersed in phosphate...
Abstract Optogenetics has transformed studies of neural circuit function, but remains challenging to apply non-human primates (NHPs). A major challenge is delivering intense, spatiotemporally-precise, patterned photostimulation across large volumes in deep tissue. Such stimulation critical, for example, modulate selectively deep-layer corticocortical feedback circuits. To address this need, we have developed the Utah Optrode Array (UOA), a 10×10 glass needle waveguide array fabricated atop...
This paper presents optical characterization of a first-generation SiO(2) optrode array as set penetrating waveguides for both optogenetic and infrared (IR) neural stimulation. Fused silica quartz discs 3-mm thickness 50-mm diameter were micromachined to yield 10 × arrays up 2-mm long optrodes at 400-μm pitch; size, length spacing may be varied along with the width tip angle. Light delivery loss mechanisms through these glass characterized. in-coupling techniques include using fibers...
We present an encapsulation scheme that combines atomic layer deposited (ALD) Al₂O₃ and Parylene C for the of implantable devices. The performances combining alumina was compared to individual layers or bilayer coating had superior properties. alumina-Parylene coated interdigitated electrodes (IDEs) soaked in PBS up nine months at temperatures from 37 80 °C accelerated lifetime testing. For 52-nm 6-μm C, leakage current ∼20 pA 5 VDC, impedance about 3.5 MΩ 1 kHz with a phase near -87°...
Implantable neural microelectrodes are integral components of neuroprosthetic technologies and can transform treatments for many neural-mediated disorders. However, dielectric material degradation during long-term (>1 year) indwelling periods restricts device functional lifetimes to a few years. This comprehensive work carefully investigates in vivo also explores the ability vitro Reactive Accelerated Aging (RAA) evaluate implant stability. Parylene C-coated Utah electrode arrays (UEAs)...
Cervical vagus nerve stimulation (VNS) is an emerging bioelectronic treatment for brain, metabolic, cardiovascular and immune disorders. Its desired off-target effects are mediated by different fiber populations knowledge of their engagement could guide calibration monitoring VNS therapies.Stimulus-evoked compound action potentials (eCAPs) directly provide information but currently not feasible in humans. A method to estimate through common, noninvasive physiological readouts be used place...
We present an electrically addressable optrode array capable of delivering light to 181 sites in the brain, each providing sufficient optogenetically excite thousands neurons <italic>in vivo</italic>, developed with aim allow behavioral studies large mammals. The device is a glass microneedle directly integrated custom fabricated microLED device, which delivers 100 needle tips and 81 interstitial surface sites, giving two-level optogenetic excitation vivo</italic>. Light delivery thermal...
We explore the long-term performance and stability of seven percutaneous Utah Slanted Electrode Arrays (USEAs) intramuscular recording leads (iEMGs) implanted chronically in residual arm nerves muscles three human participants as a means to permanently restore sensorimotor function after transradial amputations.We quantify number functional stimulating electrodes over time. also calculate signal-to-noise ratio (SNR) USEA iEMG recordings stimulation current necessary evoke detectable sensory...
Encapsulation of biomedical implants with complex three dimensional geometries is one the greatest challenges achieving long-term functionality and stability. This report presents an encapsulation scheme that combines Al(2)O(3) by atomic layer deposition parylene C for implantable electronic systems. The Al(2)O(3)-parylene bi-layer was used to encapsulate interdigitated electrodes, which were tested invitro soak testing in phosphate buffered saline solution at body temperature (37 °C)...
Abstract Vagus nerve stimulation (VNS) is a bioelectronic therapy for disorders of the brain and peripheral organs, tool to study physiology autonomic circuits. Selective activation afferent or efferent vagal fibers can maximize efficacy minimize off-target effects VNS. Anodal block (ABL) has been used achieve directional fiber in stimulation. However, evidence VNS with ABL scarce inconsistent, it unknown whether permits respect functional Through series vagotomies, we established...
This paper characterizes the Utah Slant Optrode Array (USOA) as a means to deliver infrared light deep into tissue. An undoped crystalline silicon (100) substrate was used fabricate 10 × arrays of optrodes with rows varying lengths from 0.5 mm 1.5 on 400-μm pitch. Light delivery optical fibers and loss mechanisms through these Si were characterized, primary being Fresnel reflection, coupling, radiation losses tapered shank total internal reflection in tips. Transmission at optrode tips...