30 research outputs found

    N-bit optically controlled microwave signal attenuator using the photoconductive effect

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    Various optical architectures for N-bit digital control of microwave signals are introduced that use the photoconductive (PC) effect in microwave waveguides for variable rf attenuation control. A 2-bit optically controlled microwave attenuator based on a silicon PC transmission line device is experimentally demonstrated at 990 Mhz. At 532 nm, this attenuator provided 0, 5.8, 11.2, and 15.6 of attenuation levels

    Noncontact anhysteric curve plotter and static field to time-varying hysteresisgraph with integrated temperature chamber

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    An automated, non-destructive anhysteretic magnetization characterization method for studying and modeling soft magnetic materials. This measurement method employs a “reading-waveform” that allows multiple points of reference to be established in tracing out the B waveform. In using the reference values from this waveform, the components of B that cannot be measured directly may be calculated with precision. In turn, the initial magnitude of the B waveform is identified as the unknown component of the anhysteretic state. The processes can be repeated for different values of static fields as well as a function of temperature to produce a family of anhysteretic magnetization curves. The core characterization was performed without physically altering the core, so that the true anhysteretic magnetization curve, and the true B-H loop under applied bias H, is measured

    Long-term implantable silicon carbide neural interface device using the electrical field effect

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    Field effect devices, such as capacitors and field effect transistors, are used to interact with neurons. Cubic silicon carbide is biocompatible with the neuronal environment and has the chemical and physical resilience required to withstand the body environment and does not produce toxic byproducts. It is used as a basis for generating a biocompatible semiconductor field effect device that interacts with the brain for long periods of time. The device signals capacitively and receives signals using field effect transistors. These signals can be used to drive very complicated systems such as multiple degree of freedom limb prosthetics, sensory replacements, and may additionally assist in therapies for diseases like Parkinson\u27s disease

    N-Bit Optically Controlled Microwave Signal Attenuator Using The Photoconductive Effect

    No full text
    Various optical architectures for N-bit digital control of microwave signals are introduced that use the photoconductive (PC) effect in microwave waveguides for variable rf attenuation control. A 2-bit optically controlled microwave attenuator based on a silicon PC transmission line device is experimentally demonstrated at 990 Mhz. At 532 nm, this attenuator provided 0, 5.8, 11.2, and 15.6 of attenuation levels

    N-bit optically controlled microwave signal attenuator using the photoconductive effect

    No full text
    Various optical architectures for N-bit digital control of microwave signals are introduced that use the photoconductive (PC) effect in microwave waveguides for variable rf attenuation control. A 2-bit optically controlled microwave attenuator based on a silicon PC transmission line device is experimentally demonstrated at 990 Mhz. At 532 nm, this attenuator provided 0, 5.8, 11.2, and 15.6 of attenuation levels

    Cubic silicon carbide implantable neural prosthetic

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    An implantable neuronal prosthetic and method of manufacture thereof includes at least one elongated electrode shank adapted for arrangement in the brain having at least one electrode contact disposed on its surface and arranged to electrically couple with said brain. The at least one elongated electrode shank is formed form a single crystal cubic silicon carbide. An insulation layer of amorphous, polycrystalline, or single crystal silicon carbide is disposed over the elongated electrode shank; the insulation layer of amorphous, polycrystalline, or single crystal silicon carbide is removed from the at least one electrode contact. Signal control electronics are attached to the at least one elongated electrode shank and are in electrical communication with the at least one electrode contact. In an embodiment, a plurality of the at least one elongated electrode shanks are arranged into a matrix

    Graphene electrodes on a planar cubic silicon carbide (3C-SiC) long term implantable neuronal prosthetic device

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    Graphene, can be used to make an implantable neuronal prosthetic which can be indefinitely implanted in vivo. Graphene electrodes are placed on a 3C—SiC shank and electrical insulation is provided by conformal insulating SiC. These materials are not only chemically resilient, physically durable, and have excellent electrical properties, but have demonstrated a very high degree of biocompatibility. Graphene also has a large specific capacitance in electrolytic solutions as well as a large surface area which reduces the chances for irreversible Faradaic reactions. Graphene can easily be constructed on SiC by the evaporation of Si from the surface of that material allowing for mechanically robust epitaxial graphene layers that can be fashioned into electrodes using standard lithography and etching methods

    Continuous glucose monitoring based on remote sensing of variations of parameters of a SiC implanted antenna

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    A passive sensing continuous glucose monitoring system and method of use thereof. The system includes a passive antenna formed of biocompatible silicon carbide (SiC), modeled to a desired frequency, which is permanently implanted subcutaneously. The system further includes an external-to-the-body transmitting antenna to detect changes in the blood glucose level by sending a radio signal at the frequency of the implanted passive antenna into the body. This signal is received and reflected by the passive antenna, and the reflected signal is then received at an external-to-the-body receiving antenna. Changes in the glucose level lead to modifications in the signal and can be used to determine the blood glucose level externally
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