Abstract: A negative capacitance converter is used in combination with a buffer circuit to form an electrical shunt circuit. The negative capacitance converter and the buffer circuit, together, minimize or eliminate oscillations of a negative impedance generated by the electrical shunt circuit. Additionally, a specific configuration of the negative capacitance converter is used to provide optimum stability. The buffer circuit includes a Riordan-type circuit, with the negative capacitance converter being substituted for one of the impedance elements of the Riordan-type circuit. Resistors are used to replace the other impedance elements of the Riordan-type circuit. An additional capacitor is placed across one of the operational amplifiers of the Riordan-type circuit, in order to provide additional stability.

Abstract: A method for embedding piezoelectric ceramic transducers in thermoplastic composites. The piezoelectric ceramic transducer to be embedded in a graphite/PEEK composite is first bonded with two fine silver wires for electrical connection, one on each major surface. The bonding agent is a high temperature conductive adhesive compound, such as a silver/glass frit. The fusing of the frit bonding agent is done in an over at a high temperature (i.e. 600.degree. F. or higher) for 5 to 10 minutes. Bonds are applied at several discrete spots on the zig zag wire which relieves thermal stresses induced during cooling due to a mismatch of the coefficient of thermal expansion between the ceramic material and the wire. After the connecting wires are attached, the wires and transducer are wrapped with several plies of insulating glass/PEEK cloth to prevent electrical shorting between the two silver wires through the graphite/PEEK host.

Abstract: This invention consists of a method for embedding piezoelectric ceramic transducers in thermoplastic composites. The piezoelectric ceramic transducer to be embedded in a graphite/PEEK composite is first bonded with two fine silver wires for electrical connection, one on each major surface. The bonding agent is a high temperature conductive adhesive compound, such as a silver/glass frit. The fusing of the frit bonding agent is done in an over at, a high temperature (i.e. 600.degree. F. or higher) for 5 to 10 minutes. Bonds are applied at several discrete spots on the zig zag wire which relieves thermal stresses induced during cooling due to a mismatch of the coefficient of thermal expansion between the ceramic material and the wire. After the connecting wires are attached, the wires and transducer are wrapped with several plies of insulating glass/PEEK cloth to prevent electrical shorting between the two silver wires through the graphite/PEEK host.

Abstract: In a system for in-situ delamination detection in composites, the invention employs a system which evaluates the mechanical vibration response of composite material structures. The damping characteristics of the composite structure are extracted from the detected wave properties generated by imbedded piezoelectric ceramic actuators and received by imbedded high strain sensitive fiber optic sensors. Such a sensor system is simple to operate for real-time non-destructive strain and displacement monitoring and delamination detection, without the need to remove the tested surface from operation.During the routine structural integrity monitoring operation, mechanical vibration pulses are launched into the composite from one actuator. The strain signal's propagation patterns are measured in real time by the fiber-optic sensors at different grating locations. Different travel times are computed dependent on the location of the receiving gratings.

Abstract: A mechanical vibration control device includes a piezoelectric material having a pair of electrical leads extending therefrom, and a shunt circuit connected across the electrical leads of the piezoelectric material. The shunt circuit includes an energy dissipation circuit element having a dissipation element resistor, and a frequency tuning element inductor connected in parallel with the dissipation element resistor. To reduce and damp multiple vibrational modes, multiple shunt circuits are added in parallel. The various shunt circuits are isolated from each other with an isolator circuit element connected in series with each energy dissipation circuit element. The isolator circuit element includes an isolator element capacitor, and an isolator element inductor connected in parallel with the isolator element capacitor.

Abstract: A complementary metal-ferroelectric-semiconductor transistor structure (MFST) in which an n-channel MFST is electrically coupled to a p-channel MFST in complementary fashion with the source of the n-channel MFST connected to the drain of the p-channel MFST and the drain of the n-channel MFST connected to the source of the p-channel MFST. The memory element is controlled in response to a polarizing voltage, and erasing voltage, a reference signal, and input signals such that the input signals are compared with respect to the reference signal. A matrix of memory elements arranged in rows and columns is also described with each of the memory elements comprised of a complementary MFST structure.

Abstract: A method of forming interconnections is described wherein small gaps between contacts are bridged by electroplating metal onto both contacts to form a conductive path therebetween. Many interconnections may be made simultaneously between adjacent contacts by bridging the gap with metal by electroplating.

Abstract: An electrostatically bonded dielectric-on semiconductor device, such as a ferroelectric field-effect transistor or amplifying acoustic surface wave transducer, is made with a dielectric body having properties selected from the group consisting of ferroelectricity and piezoelectricity. The dielectric body has opposed first and second major surfaces, with at least said first major surface of planar configuration to which a semiconductor body is electrostatically bonded. The semiconductor body is of a bulk material and a given conductivity type, and has first and second opposed major surfaces, with at least the first major surface of planar configuration where the semiconductor body is electrostatically bonded. At least one and typically a plurality of electrodes are positioned on the dielectric body to provide for interaction between transport carriers in the semiconductor body and electric polarization changes in the dielectric body. Preferably, the dielectric-on-semiconductor is made by the method described.

Abstract: A pyroelectric-field effect electromagnetic radiation detector is comprised of a semiconductor body having opposed major surfaces. First and second electrodes are spaced apart from each other in ohmic contact with said semiconductor body to form a conductive channel in said body between said electrodes. A pyroelectric body having opposed major surfaces substantially normal to a polar axis thereof is positioned with one said major surface in intimate contact with and preferably electrostatically bonded to a major surface of said semiconductor body at least between said electrodes, and polarized therethrough substantially normal to said opposed major surfaces at least between said first and second electrodes. A gate electrode capable of absorbing radiation to be detected is also positioned adjacent said pyroelectric body at least between said electrodes. Alternatively, the semiconductor and pyroelectric bodies may be provided by a single body having both pyroelectric and semiconductor properties.