摘要:
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.
摘要:
The microfabricated prosthetic device uses local, direct, and wavelength-specific optical stimulation to achieve an action potential from a single or small group of neurons within the central nervous system (CNS). The device is biocompatible, mechanically flexible, and optically transparent. The device can also use integrated electrodes for additional input/output (IO) locations, signal verification, feedback, wireless communication, and characterization of the electrochemically-evoked potential received from the activated neuron. The purpose of the device is to act as a neural interface prosthetic. The prosthetic is designed as the central component of a brain machine interface (BMI).
摘要:
Devices and methods for fabricating wholly silicon carbide heterojunction bipolar transistors (HBTs) using germanium base doping to produce suitable emitter/base heterojunctions. In one variation, all device layers are are grown epitaxially and the heterojunction is created by introducing a pseudoalloying material, such as germanium, to form a graded implant. In other variations, the device epitaxial layers are 1) grown directly onto a semi-insulating substrate, 2) the semi-insulating epitaxial layer is grown onto a conducting substrate; 3) the subcollector is grown on a lightly doped p-type epitaxial layer grown on a conducting substrate; and 4) the subcollector is grown directly on a conducting substrate. Another variation comprises a multi-finger HBT with bridging conductor connections among emitter fingers. Yet another variation includes growth of layers using dopants other than nitrogent or aluminum. Yet another variation includes implantation of region within one or more epitaxial layers, rather than use of separate epitaxial layers.
摘要:
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's disease.
摘要:
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.
摘要:
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.
摘要:
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's disease.
摘要:
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.
摘要:
A photoconductive spread-spectrum communications system that includes a tsmitter and a receiver. The transmitter includes an oscillating laser, a Pockels' cell, a delay cell, a photoconductive switch, and an antenna for transmitting an electromagnetic spread-spectrum signal. The receiver includes an oscillating laser, a Pockels' cell, an antenna for receiving a spread-spectrum signal, a photoconductive switch, a filter, and a threshold detector for regenerating the signal contained within the spread-spectrum transmission.
摘要:
A monolithic microwave integrated circuit is enclosed within an ionizable gas filled housing having a terminal protection device integral with the circuit's substrate. A photon generating region extends within the substrate and along a portion of the surface area of the substrate for facilitating the ionizing of the gas. First and second electrodes, in contact with the substrate surface area and disposed on opposite sides of the photon generating region, have a plurality of cantilevered protrusions extending over the surface of the substrate and equally spaced from one another forming spark-gaps therebetween. One electrode is connected to an input to the device while the other is connected to ground. When a potential difference between the first and second electrodes increases towards a predetermined value, due to high RF input energy, the photon generating region is operatively biased to emit photons, which ionize the gas, resulting in a voltage discharge across the spark-gaps to occur quickly and at a lower voltage than the semiconductor breakdown voltage.