Abstract: In one aspect, the present subject matter is directed to a sensor. The sensor includes an encapsulated fiber optic sensor and a ring shaped structure. The encapsulated fiber optic sensor passes through the ring shaped structure. The ring shaped structure is configured to resonate at a predetermined frequency.

Abstract: Active carbon filters and systems that are operative to detect active carbon filter degradations are provided. The active carbon filter can include a carbon filter comprising activated carbon and defining a filter surface; a first piezoelectric wafer active sensor on the filter surface that is electrically isolated from the carbon filter; and a second piezoelectric wafer active sensor on the filter surface that is electrically connected to the filter surface; and an impedance monitoring device electrically connected to the first piezoelectric wafer active sensor and the second piezoelectric wafer active sensor. Methods are also disclosed for determining if any degradation has occurred in an active carbon filter.

Abstract: Active carbon filters and systems that are operative to detect active carbon filter degradations are provided. The active carbon filter can include a carbon filter comprising activated carbon and defining a filter surface; a first piezoelectric wafer active sensor on the filter surface that is electrically isolated from the carbon filter; and a second piezoelectric wafer active sensor on the filter surface that is electrically connected to the filter surface; and an impedance monitoring device electrically connected to the first piezoelectric wafer active sensor and the second piezoelectric wafer active sensor. Methods are also disclosed for determining if any degradation has occurred in an active carbon filter.

Abstract: Active carbon filters and systems that are operative to detect active carbon filter degradations are provided. The active carbon filter can include a carbon filter comprising activated carbon and defining a filter surface; a first piezoelectric wafer active sensor on the filter surface that is electrically isolated from the carbon filter; and a second piezoelectric wafer active sensor on the filter surface that is electrically connected to the filter surface; and an impedance monitoring device electrically connected to the first piezoelectric wafer active sensor and the second piezoelectric wafer active sensor. Methods are also disclosed for determining if any degradation has occurred in an active carbon filter.

Abstract: Active carbon filters and systems that are operative to detect active carbon filter degradations are provided. The active carbon filter can include a carbon filter comprising activated carbon and defining a filter surface; a first piezoelectric wafer active sensor on the filter surface that is electrically isolated from the carbon filter; and a second piezoelectric wafer active sensor on the filter surface that is electrically connected to the filter surface; and an impedance monitoring device electrically connected to the first piezoelectric wafer active sensor and the second piezoelectric wafer active sensor. Methods are also disclosed for determining if any degradation has occurred in an active carbon filter.

Abstract: Methods of forming a molded composite material are generally provided. A composite forming precursor (e.g., fibers and/or a resin material) can be applied onto a mold that includes a plurality of piezoelectric sensors embedded into the mold. The composite forming precursor can then be cured adjacent to the mold to form a molded composite material. During curing, the molded composite material can be monitored, using the piezoelectric sensors to detect any defects formed during curing.

Abstract: A piezoelectric sensor having a plurality of electrodes deposited on a single surface of the dielectric medium is generally provided. The plurality of electrodes can define a plurality of square-shaped electrodes forming a grid on the first surface of the dielectric medium while the second electrode defines a continuous electrode. An electrode border surrounding the plurality of electrodes can be deposited on the first surface of the dielectric medium. Alternatively, the plurality of electrodes can define column-shaped electrodes, while the second electrode defines a plurality of row-shaped electrodes separated by etchings. The direction of orientation of each column-shaped electrode and the direction of orientation of each row-shaped electrode can be substantially perpendicular. A method of making a piezoelectric sensor is also provided.

Abstract: Disclosed is an apparatus and methodology for structural health monitoring (SHM) in which smart devices interrogate structural components to predict failure, expedite needed repairs, and thus increase the useful life of those components. Piezoelectric wafer active sensors (PWAS) are applied to or integrated with structural components and various data collected there from provide the ability to detect and locate cracking, corrosion, and disbanding through use of pitch-catch, pulse-echo, electro/mechanical impedance, and phased array technology. Stand alone hardware and an associated software program are provided that allow selection of multiple types of SHM investigations as well as multiple types of data analysis to perform a wholesome investigation of a structure.

Abstract: In an exemplary configuration, a system for structural health monitoring is provided. The system includes a battery-less nano-PWAS device, the device comprising an array of nano-PWAS transducers and a tag antenna.

Abstract: Disclosed is an apparatus and methodology for structural health monitoring (SHM) in which smart devices interrogate structural components to predict failure, expedite needed repairs, and thus increase the useful life of those components. Piezoelectric wafer active sensors (PWAS) are applied to or integrated with structural components and various data collected there from provide the ability to detect and locate cracking, corrosion, and disbanding through use of pitch-catch, pulse-echo, electro/mechanical impedance, and phased array technology. Stand alone hardware and an associated software program are provided that allow selection of multiple types of SHM investigations as well as multiple types of data analysis to perform a wholesome investigation of a structure.

Abstract: A piezoelectric sensor having a plurality of electrodes deposited on a single surface of the dielectric medium is generally provided. The plurality of electrodes can define a plurality of square-shaped electrodes forming a grid on the first surface of the dielectric medium while the second electrode defines a continuous electrode. An electrode border surrounding the plurality of electrodes can be deposited on the first surface of the dielectric medium. Alternatively, the plurality of electrodes can define column-shaped electrodes, while the second electrode defines a plurality of row-shaped electrodes separated by etchings. The direction of orientation of each column-shaped electrode and the direction of orientation of each row-shaped electrode can be substantially perpendicular. A method of making a piezoelectric sensor is also provided.

Abstract: The present subject matter is direct to apparatus and methodologies for performing omnidirectional (360°) damage detection in a thin-wall structure using a planar embedded piezoelectric wafer active sensors (PWAS) phased array. Virtual beamforming for the array is implemented through either a transmission process by selective energizing selected sensors or by a signal post-processing procedure. Sensors may be embedded in a thin-walled structure as planar or circular arrays to achieve omnidirectional damage detection.

Abstract: Disclosed is an apparatus and methodology for monitoring the health of a structure. Apparatus and methodologies are disclosed for applying a controlled signal sequence to an array of piezoelectric wafer active sensors and for analyzing echo returns from the applied signals to determine the health of the monitored structure. The applied signal may take on certain characteristics including being provided as a specially tailored chirp signal to compensate for non-linear characteristics of the monitored structure.

Abstract: A small, lightweight, portable, and inexpensive self-processing integrated damage assessment sensor (SPIDAS) that may be temporarily or permanently attached to a structure for structural health monitoring is provided. The SPIDAS device employs an electromechanical impedance measuring method to directly measure the high-frequency local impedance spectrum of the structure, process the electromechanical impedance data, and issue structural health reports that the device may transmit over a wireless connection.

Abstract: A method of detecting a damaged feature within a structure includes embedding a plurality of thin piezoelectric ceramic sensors on the structure. A first sensor is excited so that the first sensor produces a responsive signal in the structure. The responsive signal is received at a second sensor. The presence or absence in the received responsive signal of at least one predetermined signal characteristic is determined, where the predetermined signal characteristic is related to existence of the damage feature.

Abstract: A method and device for performing ultrasonic damage detection in a thin-wall structure using an array of embedded Piezoelectric Wafer Active Sensors (PWAS) for the transmission and reception of guided waves and a signal processing methodology based on the beamforming process. The beamforming signal processing has been adapted to the specifics of guided elastic waves traveling in thin-wall structures.

Abstract: A method and device for performing ultrasonic damage detection in a thin-wall structure using an array of embedded Piezoelectric Wafer Active Sensors (PWAS) for the transmission and reception of guided waves and a signal processing methodology based on the beamforming process. The beamforming signal processing has been adapted to the specifics of guided elastic waves traveling in thin-wall structures.

Abstract: A small, lightweight, portable, and inexpensive self-processing integrated damage assessment sensor (SPIDAS) that may be temporarily or permanently attached to a structure for structural health monitoring is provided. The SPIDAS device employs an electromechanical impedance measuring method to directly measure the high-frequency local impedance spectrum of the structure, process the electromechanical impedance data, and issue structural health reports that the device may transmit over a wireless connection.

Abstract: A method of detecting a damaged feature within a structure includes embedding a plurality of thin piezoelectric ceramic sensors on the structure. A first sensor is excited so that the first sensor produces a responsive signal in the structure. The responsive signal is received at a second sensor. The presence or absence in the received responsive signal of at least one predetermined signal characteristic is determined, where the predetermined signal characteristic is related to existence of the damage feature.