Abstract: A method and apparatus for determining an electrical property of a structure. The method involves creating a model of an electrical property of a structure and measuring the electrical property of the structure between at least two of a plurality of locations. The method also involves determining the electrical property of at least a portion of the structure based on the model and the measurement of the electrical property between the at least two of the plurality of locations.

Abstract: Systems and methods associated with a fluid-activated shaft seal are provided. The system includes a housing and a seal disposed relative to the housing. The method reduces flow of a fluid between the shaft and the housing. The method involves installing the housing in an opening relative to the shaft and locating the seal relative to the housing. The seal includes a gel material that expands when exposed to a fluid. The seal reduces flow of the fluid through a gap between the housing and the shaft. Advantages of the system and method include reduced wear to the seal due to friction because the seal does not engage the shaft in the absence of a fluid. The seal engages the shaft in the presence of a fluid. Sealing quality is improved by increasing the pressure differential acting on the gel material. In some embodiments, the seal includes a lip portion.

Abstract: A method and apparatus for controlled charging of photoluminescent materials are provided. The method involves receiving a signal associated with an operating property of a luminescent system and determining if the signal satisfies an operating criterion. Electromagnetic energy is provided to the photoluminescent material until an ambient light level in proximity to the system exceeds a predefined level. The system includes a photoluminescent material and a sensor for detecting an operating property of the luminescent system. The system includes a control module for selectively illuminating the photoluminescent material based on the operating property until the ambient light level in proximity to the luminescent system exceeds a predefined level.

Abstract: Laser beam machining is applied to form arbitrarily shaped electroactive ceramics for transducers (e.g., electromechanical sensors and actuators). One particularly preferred embodiment of the invention comprises machining parallel grooves in a ceramic plate to improve flexibility. The grooves provide strain relief in bending by relieving Poisson strains transverse to the direction of bending. This embodiment offers the further benefit that planar anisotropy or directionality is introduced in the transducer. The machining process of the invention further enables the production of more complex geometries than those currently known in the art. Because of the flexibility of the machining process, virtually any desired transducer shape may be produced.

Abstract: A method and apparatus for determining an electrical property of a structure. The method involves creating a model of an electrical property of a structure and measuring the electrical property of the structure between at least two of a plurality of locations. The method also involves determining the electrical property of at least a portion of the structure based on the model and the measurement of the electrical property between the at least two of the plurality of locations.

Abstract: A temperature regulation and flow control device is described. A web of material, e.g., for a wet suit, has a layer of gel particles embedded in a flow control layer, preferably a foam matrix. A water permeable neoprene layer covers the flow control layer and allows water to enter the suit. The flow of water in the suit is regulated by the expansion and contraction of the gel as it undergoes a volume phase transition in response to a change in temperature. When the diver is in cold water, the cold water enters the foam substrate and the gel expands, causing permeability (i.e., flow) to decrease. Flow is restricted in response to cooling, and the foam substrate expands and tightens the fit of the wet suit. In warmer water, an opposite effect occurs, whereby the gel contracts and flow increases. The gel contracts relaxing the fit of the suit. A gel having a particular volume phase transition critical temperature is selected in order to maintain body temperature in a particular environment.

Abstract: An ignition system employing a piezoelectric transformer having a drive side and an output side. The ignition system further includes circuit elements in electronic communication with the output side that tune output impedance in series with a breakdown gap to optimize power flow from the transformer to the breakdown gap after breakdown and a timing control circuit in electronic communication with the drive side that meters post-breakdown energy delivered to the breakdown gap by timing the duration of post-breakdown power flow.

Abstract: A temperature regulation and flow control device is described. A web of material, e.g., for a wet suit, has a layer of gel particles embedded in a flow control layer, preferably a foam matrix. A water permeable neoprene layer covers the flow control layer and allows water to enter the suit. The flow of water in the suit is regulated by the expansion and contraction of the gel as it undergoes a volume phase transition in response to a change in temperature. When the diver is in cold water, the cold water enters the foam substrate and the gel expands, causing permeability (i.e., flow) to decrease. Flow is restricted in response to cooling, and the foam substrate expands and tightens the fit of the wet suit. In warmer water, an opposite effect occurs, whereby the gel contracts and flow increases. The gel contracts relaxing the fit of the suit. A gel having a particular volume phase transition critical temperature is selected in order to maintain body temperature in a particular environment.

Abstract: Impact resistant components and methods of protecting structures from impacts. The components are interposed between a potential point of impact and a structure to be protected. They comprise a shape memory alloy (SMA) exhibiting pseudoelastic behavior, and having a high strain to failure.

Abstract: The present invention comprises a piezoelectric transformer having substantially improved performance. The piezoelectric element is composed of a single crystal of a relaxor ferroelectric piezoelectric material. This element is coupled to input and output electrodes. The element vibrates mechanically in response to an input signal, which causes an output signal to be generated at the output electrodes. Improved power transmission is observed despite the reduced mechanical Q of the single crystal material, because the coupling and dielectric strength of the material are improved relative to polycrystals.

Abstract: An article and method for measuring strain using a strain gauge made of a shape memory y alloy, and preferably a pseudoelastic alloy, is disclosed. The strain gauge includes an element that preferably is attached to a substrate and mounted on an object, or is woven or stitched to a fabric to measure the strain experienced under an applied stress. The preferred pseudoelastic alloy is Nitinol, which in pseudoelastic form can elongate by up to approximately 8% to accommodate strain in an object or fabric. When woven into a fabric, a Nitinol-based strain gauge can measure strains of up to approximately 20% in the fabric. The strain gauge can be used in such applications as automotive and aircraft seatbelts, parachute canopies and static lines, and commercial cargo nets.

Abstract: A temperature regulation and flow control device is described. A web of material, e.g., for a wet suit, has a layer of gel particles embedded in a flow control layer, preferably a foam matrix. A water permeable neoprene layer covers the flow control layer and allows water to enter the suit. The flow of water in the suit is regulated by the expansion and contraction of the gel as it undergoes a volume phase transition in response to a change in temperature. When the diver is in cold water, the cold water enters the foam substrate and the gel expands, causing permeability (i.e., flow) to decrease. Flow is restricted in response to cooling, and the foam substrate expands and tightens the fit of the wet suit. In warmer water, an opposite effect occurs, whereby the gel contracts and flow increases. The gel contracts relaxing the fit of the suit. A gel having a particular volume phase transition critical temperature is selected in order to maintain body temperature in a particular environment.

Abstract: An improved spark ignition system. Pressure on a piezoelectric element results in a voltage that, when discharged across a spark gap, causes dielectric breakdown in a fuel air mixture. Additional current to power combustion is supplied by a capacitor circuit. The ignition system increases the combustion rate and decreases emissions of NOx.

Abstract: An variable shaft, for example for a golf club. A hollow shaft has a cable or wire in the center, and means for varying the tension of the cable or wire. Increasing tension on the cable or wire places the shaft in compression and thereby reduces its bending stiffness. Preferably, the variation means are designed so that the wire tension may be quickly and easily varied by the user.

Abstract: A spark plug comprising a piezoelectric element that strains with the increase in pressure in the cylinder of an internal combustion engine, and methods of making and using such a spark plug. The strain on the element generates a voltage across the poles of the piezoelectric element that varies with the cylinder pressure. This voltage can be monitored to determine the pressure in the cylinder. The voltage will increase until it is sufficient to create a spark between two poles that will be used to ignite the fuel-air mixture in the cylinder. The voltage may be further increased by using the increasing cylinder pressure to accelerate a striker mass to impact the piezoelectric element. After ignition, the piezoelectric element strains further because of the rapid increase in pressure due to the combustion process. Sensing the voltage output after combustion can provide information about the engine cycle and indicate any anomalies such as pre-ignition, misfire, or knock.