Abstract: A helmet system includes a helmet shell and a battery interface. The battery interface may be disposed on an exterior of a rear portion of the helmet shell. The battery interface may include a base, a mechanical latch feature, and a magnetic latch feature. The mechanical latch feature may be configured to interface with a complementary mechanical feature of the battery to contribute to a releasable maintenance of the battery within the battery receiving slot. The magnetic latch feature may be configured to interface, via a magnetic bias, with a complementary magnetic feature of the battery to contribute to the releasable maintenance of the battery within the battery receiving slot.

Abstract: An antenna includes a top plate having a top side and a bottom side, a ground plate disposed parallel to the top plate, a ground pin connecting the top plate to the ground plate, and a probe pin connected to the bottom side of the top plate. The probe pin is configured to be connected to a signal source. The antenna further includes a first dielectric layer adjacent to the bottom side of the top plate, and a first patterned conductor layer adjacent to the first dielectric layer. The first dielectric layer is disposed between the top plate and the first patterned conductor layer. The top plate is separated from the ground plate by a distance.

Abstract: An antenna includes a top plate having a top side and a bottom side, a ground plate disposed parallel to the top plate, a ground pin connecting the top plate to the ground plate, and a probe pin connected to the bottom side of the top plate. The probe pin is configured to be connected to a signal source. The antenna further includes a first dielectric layer adjacent to the bottom side of the top plate, and a first patterned conductor layer adjacent to the first dielectric layer. The first dielectric layer is disposed between the top plate and the first patterned conductor layer. The top plate is separated from the ground plate by a distance.

Abstract: A fastener is configured to maintain electromagnetic interference characteristics of metamaterial shielding. The fastener includes a head having an interior side and an exterior side, a shank extending from the interior side of the head and configured to be driven into a receiving surface, and a seal being formed as a loop and disposed on the interior side of the head. The seal may include a conductive material.

Abstract: Electromagnetic shielding systems, apparatuses, and method are provided. One apparatus is an example free-space absorber metamaterial that includes a first array of patches disposed at a first plane, a conductive backplane disposed at a structural surface plane, and a first dielectric spacer disposed between the first array of patches and the conductive backplane. A first bandwidth of absorption for the free-space absorber metamaterial may be based on the area of a patch in the first array of patches, the first electrical resistance of a patch in the first array of patches, and the first gap distance taken between the first array of patches and the conductive backplane.

Abstract: A radio frequency surface wave attenuator structure is provided. The structure may be configured to be operably coupled with a plurality of other radio frequency surface wave attenuator structures to form a metamaterial. The radio frequency surface wave attenuator structure may include a patch disposed in a first plane and defining a patch area and a backplane disposed in a second plane and extending along the second plane to be shared with the other surface wave attenuator structures. The structure may further include a via spring having a number of turns and being comprised of a conductive material. The via spring may electrically couple the patch to the backplane. The structure may further include a dielectric disposed between the patch and the backplane.

Abstract: Electromagnetic shielding systems, apparatuses, and method are provided. One apparatus is an example free-space absorber metamaterial that includes a first array of patches disposed at a first plane, a conductive backplane disposed at a structural surface plane, and a first dielectric spacer disposed between the first array of patches and the conductive backplane. A first bandwidth of absorption for the free-space absorber metamaterial may be based on the area of a patch in the first array of patches, the first electrical resistance of a patch in the first array of patches, and the first gap distance taken between the first array of patches and the conductive backplane.

Abstract: A fastener is configured to maintain electromagnetic interference characteristics of metamaterial shielding. The fastener includes a head having an interior side and an exterior side, a shank extending from the interior side of the head and configured to be driven into a receiving surface, and a seal being formed as a loop and disposed on the interior side of the head. The seal may include a conductive material.

Abstract: An antenna is provided including an electromagnetic metasurface. The electromagnetic characteristics of the antenna are dynamically tunable.

Abstract: A radio frequency surface wave attenuator structure is provided. The structure may be configured to be operably coupled with a plurality of other radio frequency surface wave attenuator structures to form a metamaterial. The radio frequency surface wave attenuator structure may include a patch disposed in a first plane and defining a patch area and a backplane disposed in a second plane and extending along the second plane to be shared with the other surface wave attenuator structures. The structure may further include a via spring having a number of turns and being comprised of a conductive material. The via spring may electrically couple the patch to the backplane. The structure may further include a dielectric disposed between the patch and the backplane.

Abstract: A method and device are provided for manipulating high-speed flows without moving aerodynamic structures. More particularly, a flow control actuator device is provided that is capable of producing a pulsating synthetic jet with high exhaust velocities for manipulating high-speed flows without moving aerodynamic structures. The high exhaust velocities of the actuator device may reach sonic levels of Mach 1 or greater. In one embodiment, the device may be constructed as an array of devices. In such an embodiment, each individual device is preferably reduced to a very small size. In such an embodiment, each individual device can then be fired in temporal patterns to create high-speed synthetic jets of air extending above the surface of the each device.

Abstract: A method and device are provided for manipulating high-speed flows without moving aerodynamic structures. More particularly, a flow control actuator device is provided that is capable of producing a pulsating synthetic jet with high exhaust velocities for manipulating high-speed flows without moving aerodynamic structures. The high exhaust velocities of the actuator device may reach sonic levels of Mach 1 or greater. In one embodiment, the device may be constructed as an array of devices. In such an embodiment, each individual device is preferably reduced to a very small size. In such an embodiment, each individual device can then be fired in temporal patterns to create high-speed synthetic jets of air extending above the surface of the each device.

Abstract: A non-contact method for evaluating stress in a substrate. An impurity is non-uniformly introduced into at least one region of a crystalline substrate. The crystalline substrate is subjected to physical stress. Fluorescence producing energy is directed at the crystalline substrate. A fluorescence produced by the crystalline substrate is measured. The fluorescence is correlated with the stress on the crystalline substrate.

Abstract: A long-life conductivity sensor system and method that is embeddable or immersible in a medium. The conductivity sensor system includes at least a housing with an enclosing wall that defines an interior volume and that has at least one aperture through the wall; a pair of electrodes protruding through the aperture into a medium surrounding the sensor housing; and conductivity sensing electronics contained within the sensor housing interior volume and connected to the pair of electrodes. The conductivity sensing electronics include a galvanostat connected to the electrodes for inducing discrete constant current pulses between the electrodes creating a transient voltage signal between the electrodes; and a high-speed voltmeter/A-D Converter connected to the electrodes for measuring the transient voltage signal between the electrodes, the transient voltage signal being a function of the conductivity of the medium surrounding the sensor housing.

Abstract: A non-contact method for evaluating stress in a substrate. An impurity is non-uniformly introduced into at least one region of a crystalline substrate. The crystalline substrate is subjected to physical stress. Fluorescence producing energy is directed at the crystalline substrate. A fluorescence produced by the crystalline substrate is measured. The fluorescence is correlated with the stress on the crystalline substrate.

Abstract: A multi-functional sensor system for simultaneously monitoring various parameters such as the structural, chemical and environmental conditions associated with a medium to be monitored, e.g., bridges, high-rise buildings, pollution zones, is provided wherein the system includes at least a plurality of wireless multi-functional sensor platforms embedded in the medium in which an interrogation unit transmits power and receives responses. Each wireless multi-functional sensor platform includes multiple channels for accommodating a plurality of sensor types to simultaneously monitor the parameters associated with the medium. Thus, the wireless sensor platforms are formed to include those sensor types which are considered germane to the intended medium to be monitored.

Abstract: A non-contact method for evaluating stress in a substrate. An impurity is non-uniformly introduced into at least one region of a crystalline substrate. The crystalline substrate is subjected to physical stress. Fluorescence producing energy is directed at the crystalline substrate. A fluorescence produced by the crystalline substrate is measured. The fluorescence is correlated with the stress on the crystalline substrate.

Abstract: A long-life conductivity sensor system and method that is embeddable or immersible in a medium. The conductivity sensor system includes at least a housing with an enclosing wall that defines an interior volume and that has at least one aperture through the wall; a pair of electrodes protruding through the aperture into a medium surrounding the sensor housing; and conductivity sensing electronics contained within the sensor housing interior volume and connected to the pair of electrodes. The conductivity sensing electronics include a galvanostat connected to the electrodes for inducing discrete constant current pulses between the electrodes creating a transient voltage signal between the electrodes; and a high-speed voltmeter/A-D Converter connected to the electrodes for measuring the transient voltage signal between the electrodes, the transient voltage signal being a function of the conductivity of the medium surrounding the sensor housing.

Abstract: The Spark Jet can manipulate high-speed flows without moving aerodynamic structures and generates exhaust streams that can penetrate supersonic (as well as subsonic) boundary layers without the need for active mechanical components. The Spark Jet comprises a chamber with embedded electrodes and a discharging orifice. High-chamber pressure may be generated by rapidly heating the gas inside SparkJet using an electrical or other useful discharge. The pressure may be relieved by exhausting the heated air though an orifice.

Abstract: A non-contact method for evaluating stress in a substrate. An impurity is non-uniformly introduced into at least one region of a crystalline substrate. The crystalline substrate is subjected to physical stress. Fluorescence producing energy is directed at the crystalline substrate. A fluorescence produced by the crystalline substrate is measured. The fluorescence is correlated with the stress on the crystalline substrate.