SUPPLEMENTAL SENSOR MODES AND SYSTEMS FOR ULTRASONIC TRANSDUCERS
First Claim
1. A Piezoelectric Micromachined Ultrasonic Transducer (PMUT) device comprising:
- a substrate;
an edge support structure connected to the substrate;
a membrane connected to the edge support structure such that a cavity is defined between the membrane and the substrate, the membrane configured to allow movement at ultrasonic frequencies, the membrane comprising;
a piezoelectric layer;
an electrode coupled to a first side of the piezoelectric layer;
a first pair of interdigitated electrodes coupled to a second side of the piezoelectric layer, the first side and the second side on opposite sides of the piezoelectric layer; and
a second pair of interdigitated electrodes coupled to the second side of the piezoelectric layer; and
wherein the PMUT is configured to operate in a Surface Acoustic Wave (SAW) mode.
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Accused Products
Abstract
A Piezoelectric Micromachined Ultrasonic Transducer (PMUT) device is provided. The PMUT includes a substrate and an edge support structure connected to the substrate. A membrane is connected to the edge support structure such that a cavity is defined between the membrane and the substrate, where the membrane configured to allow movement at ultrasonic frequencies. The membrane comprises a piezoelectric layer and first and second electrodes coupled to opposing sides of the piezoelectric layer. For operation in a Capacitive Micromachined Ultrasonic Transducer (CMUT) mode, a third electrode is disposed on the substrate and separated by an air gap in the cavity from the second electrode. Also provided are an integrated MEMS array, a method for operating an array of PMUT/CMUT dual-mode devices, and a PMUT/CMUT dual-mode device.
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Citations
20 Claims
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1. A Piezoelectric Micromachined Ultrasonic Transducer (PMUT) device comprising:
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a substrate; an edge support structure connected to the substrate; a membrane connected to the edge support structure such that a cavity is defined between the membrane and the substrate, the membrane configured to allow movement at ultrasonic frequencies, the membrane comprising; a piezoelectric layer; an electrode coupled to a first side of the piezoelectric layer; a first pair of interdigitated electrodes coupled to a second side of the piezoelectric layer, the first side and the second side on opposite sides of the piezoelectric layer; and a second pair of interdigitated electrodes coupled to the second side of the piezoelectric layer; and wherein the PMUT is configured to operate in a Surface Acoustic Wave (SAW) mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An integrated MEMS array comprising:
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a plurality of MEMS Piezoelectric Micromachined Ultrasonic Transducers (PMUTs) for transmitting ultrasonic beams and receiving ultrasonic signals; wherein at least a portion of the PMUTs are operable in two modes;
a surface acoustic wave (SAW) mode and an ultrasonic mode. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A method for operating an array of Piezoelectric Micromachined Ultrasonic Transducer (PMUT)/surface acoustic wave (SAW) dual-mode devices, each dual-mode device comprising a membrane comprising a piezoelectric layer, an electrode coupled to a first side of the piezoelectric layer, a first pair of interdigitated electrodes coupled to a second side of the piezoelectric layer, the first side and the second side on opposite sides of the piezoelectric layer, and a second pair of interdigitated electrodes coupled to the second side of the piezoelectric layer, the method comprising:
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selecting a SAW mode by placing an AC voltage on a first interdigitated electrode of the first pair of interdigitated electrodes and a first interdigitated electrode of the second pair of interdigitated electrodes to generate a surface acoustic wave on the second side of the piezoelectric layer;
orselecting a PMUT mode by driving the first pair of interdigitated electrodes and the second pair of interdigitated electrodes with a first potential and driving the electrode with a second potential, causing the PMUT device to produce a flexural mode of motion in the membrane; and selectively switching between the PMUT mode and the SAW mode, wherein sensing can occur in either of the PMUT mode and the SAW mode. - View Dependent Claims (20)
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Specification