Abstract: A multi-resonator-based system responsive to acoustic waves includes at least two resonators, each including a bottom plate, side walls secured to the bottom plate, and a top plate disposed on top of the side walls. The top plate includes an orifice so that a portion of an incident acoustical wave compresses gas in the resonators. The bottom plate or the side walls include at least one compliant portion. A reciprocal electromechanical transducer coupled to the compliant portion of each of the resonators forms a first and second transducer/compliant composite. An electrical network is disposed between the reciprocal electromechanical transducer of the first and second resonator.

Abstract: An electromechanical floating element shear-stress sensor, which may also be referred to as a flow rate sensor, having one or more transduction mechanisms coupled to a support arm of a floating element wafer such that the transduction mechanisms are normal to the force applied to a top surface of the floating element. The transduction mechanisms may be generally attached to a side surface of one or more arms supporting the floating element and may be coupled together and to a processor using one or more contacts extending from the backside of the floating element sensor. Thus, the floating element shear-stress sensor may have an unobstructed surface past which a fluid may flow. The floating element may also include a temperature sensing system for accounting for affects of temperature on the floating element system.

Abstract: An integrated MEMS resonant generator system includes a substrate, a plurality of piezoelectric micro generators disposed on the substrate, the micro generators each generating a voltage output in response to vibrational energy received, and at least one power processor disposed on the substrate. The power processor electrically coupled to outputs of the plurality of micro generators. When the input conditions change, the power processor can dynamically adjust its switching functions to optimize the power delivered to a load or energy storage reservoir.

Abstract: A system responsive to acoustic waves includes a resonator having a bottom plate, side walls secured to the bottom plate, and a top plate disposed on top of the side walls. The top plate includes an orifice. The bottom plate or side walls of the resonator include at least one compliant portion. A reciprocal electromechanical transducer is coupled to the compliant portion of the resonator to form a transducer/compliant composite, wherein the transducer/compliant composite has an open circuit acoustic impedance. An electrical network is coupled to the transducer/compliant composite. The acoustic impedance of the transducer/compliant composite copied to the electrical network is different as compared to the open circuit impedance which perm its the frequency response of the system to be varied over a large range of frequencies.

Abstract: A method and system are provided for reducing flow-induced resonance in a cavity of a structure. At least one pair of diaphragms are mounted in a housing and separated from one another such that a chamber is formed therebetween within the housing. A first diaphragm of the pair of diaphragms is oscillated in accordance with a time-varying function. A second diaphragm of the pair of diaphragms is oscillated inversely to the first diaphragm so that pressure in the chamber formed therebetween changes in correspondence with the time-varying function. The chamber is vented at a position flush with the surface of the structure along the leading edge of the cavity. As a result of such venting, the pressure in the chamber that changes in correspondence with the time-varying function introduces a corresponding time-varying disturbance into the shear layer along the leading edge of the cavity.

Abstract: A method and system are provided for reducing flow-induced resonance in a structure's cavity. A time-varying disturbance is introduced into the flow along a leading edge of the cavity. The time-varying disturbance can be periodic and can have the same or different frequency of the natural resonant frequency of the cavity. In one embodiment of the system, flaps are mounted flush with the surface of the structure along the cavity's leading edge. A piezoelectric actuator is coupled to each flap and causes a portion of each flap to oscillate into and out of the flow in accordance with the time-varying function. Resonance reduction can be achieved with both open-loop and closed-loop configurations of the system.