Abstract: Aspects of the disclosure relate to microelectromechanical systems (MEMS) and associated detection and classification of surface impacts using MEMS systems and signals. One aspect is a device including a memory configured to store an audio signal and a motion signal and one or more processors. The processors are configured to obtain the audio signal, wherein the audio signal is generated based on detection of sound by a microphone, obtain the motion signal, wherein the motion signal is generated based on detection of motion by a motion sensor mounted on a surface of an object, perform a similarity measure based on the audio signal and the motion signal, and determine a context of a contact type of the surface of the object based on the similarity measure.

Abstract: Aspects of the disclosure relate to microelectromechanical systems (MEMS) and associated detection and classification of surface impacts using MEMS systems and signals. One aspect is a device including a memory configured to store an audio signal and a motion signal and one or more processors. The processors are configured to obtain the audio signal, wherein the audio signal is generated based on detection of sound by a microphone, obtain the motion signal, wherein the motion signal is generated based on detection of motion by a motion sensor mounted on a surface of an object, perform a similarity measure based on the audio signal and the motion signal, and determine a context of a contact type of the surface of the object based on the similarity measure.

Abstract: A transducer includes a first piezoelectric layer; and a second piezoelectric layer that is above the first piezoelectric layer; wherein the second piezoelectric layer is a more compressive layer with an average stress that is less than or more compressive than an average stress of the first piezoelectric layer.

Abstract: A low noise piezoelectric sensor, such as a piezoelectric acoustic transducer, includes a first conductive layer, a second conductive layer, and a piezoelectric layer between the first conductive layer and the second conductive layer. The piezoelectric layer comprises aluminum scandium nitride (AlScN) having a scandium content of greater than 15%, in which the scandium content and an aluminum content comprises 100% of the aluminum scandium nitride. In this way, the piezoelectric layer (or the sensor including the piezoelectric layer) achieves a dissipation factor of less than about 0.1%.

Abstract: A device comprising: a sensor; and a first circuit configured to detect when an input stimulus to the sensor satisfies one or more detection criteria, and further configured to produce a signal upon detection that causes adjustment of performance of the device; and a second circuit for processing input following detection, wherein the second circuit is configured to increase its power level following detection, relative to a power level of the second circuit prior to detection.

Abstract: Aspects include piezoelectric acoustic transducers and systems for acoustic transduction. In some aspects, an acoustic transducer is structured with a silicon substrate having a top surface and a bottom surface, where the top surface has a first portion and an edge along the first portion associated with an acoustic aperture. The transducer has a first silicon oxide layer disposed over the first portion of the top surface of the silicon substrate, a polysilicon layer disposed over the first silicon oxide layer, and a second silicon oxide layer disposed over the polysilicon layer. A cantilevered beam comprising a fixed end, a deflection end, a top surface, and a bottom surface, has a first portion of the bottom surface at the fixed end disposed over the second silicon oxide layer, where a second portion of the bottom surface at the deflection end is formed over the acoustic aperture. In some aspects.

Abstract: Aspects include piezoelectric acoustic transducers and systems for acoustic transduction. In some aspects, an acoustic transducer is structured with a silicon substrate having a top surface and a bottom surface, where the top surface has a first portion and an edge along the first portion associated with an acoustic aperture. The transducer has a first silicon oxide layer disposed over the first portion of the top surface of the silicon substrate, a polysilicon layer disposed over the first silicon oxide layer, and a second silicon oxide layer disposed over the polysilicon layer. A cantilevered beam comprising a fixed end, a deflection end, a top surface, and a bottom surface, has a first portion of the bottom surface at the fixed end disposed over the second silicon oxide layer, where a second portion of the bottom surface at the deflection end is formed over the acoustic aperture. In some aspects.

Abstract: Aspects of acoustic transducers are described. One aspect is a microelectromechanical (MEMS) transducer comprising a substrate and multiple cantilevered beams. A first cantilevered beam comprises a first protrusion and a first piezoelectric structure, where the first piezoelectric structure comprises a first deflection end and a first fixed end, where the first fixed end is coupled to the substrate, and where the first deflection end is cantilevered away from the substrate. The first cantilevered beam is separated from a second cantilevered beam by a gap. The first protrusion is disposed at the first deflection end and increases a thickness of the first cantilevered beam along the gap at the first deflection end. A second protrusion of the second beam is disposed at a second deflection end and increases a thickness of the second cantilevered beam along the gap at the second deflection end.

Abstract: A transducer of the preferred embodiment including a transducer and a plurality of adjacent, tapered cantilevered beams. Each of the beams define a beam base, a beam tip, and a beam body disposed between the beam base and the beam tip. The beams are arranged such that each of the beam tips extends toward a common area. Each beam is joined to the substrate along the beam base and is free from the substrate along the beam body. A preferred method of manufacturing a transducer can include: depositing alternating layers of piezoelectric and electrode onto the substrate in block, processing the deposited layers to define cantilever geometry in block, depositing metal traces in block, and releasing the cantilevered beams from the substrate in block.

Abstract: A transducer of the preferred embodiment including a transducer and a plurality of adjacent, tapered cantilevered beams. Each of the beams define a beam base, a beam tip, and a beam body disposed between the beam base and the beam tip. The beams are arranged such that each of the beam tips extends toward a common area. Each beam is joined to the substrate along the beam base and is free from the substrate along the beam body. A preferred method of manufacturing a transducer can include: depositing alternating layers of piezoelectric and electrode onto the substrate in block, processing the deposited layers to define cantilever geometry in block, depositing metal traces in block, and releasing the cantilevered beams from the substrate in block.