A micromachined ultrasonic transducer (MUT). The MUT includes: a substrate; a membrane suspending from the substrate; a bottom electrode disposed on the membrane; a piezoelectric layer disposed on the bottom electrode and an asymmetric top electrode is disposed on the piezoelectric layer. The areal density distribution of the asymmetric electrode along an axis has a plurality of local maxima, wherein locations of the plurality of local maxima coincide with locations where a plurality of anti-nodal points at a vibrational resonance frequency is located.

A sensor using ultrasound to detect presence and nature of analyte includes an ultrasonic element and a receptor thereon. The ultrasonic element includes a first electrode, a second electrode facing and spaced apart from the first electrode, an insulating layer between the first electrode and the second electrode, and a vibrating film between the insulating layer and the first electrode. The vibrating film carries the first electrode. A cavity is formed between the vibrating film and the insulating layer. The receptor is on a side of the first electrode away from the second electrode. The receptor can combine with a target substance in a test analyte. When the first electrode and the second electrode are applied with different voltages, certain ultrasound frequencies are generated as the vibrating film vibrates, and the presence and weight of different target substances are indicated by the changes in resonance.

Disclosed are systems and methods of operation for capacitive radio frequency micro-electromechanical switches, such as CMUT cells for use in an ultrasound system. An RFMEMS may include substrate, a first electrode connected to the substrate, a membrane and a second electrode connected to the membrane.

Aspects of the technology described herein relate to built-in self-testing (BIST) of circuitry (e.g., a pulser or receive circuitry) and/or transducers in an ultrasound device. A BIST circuit may include a transconductance amplifier coupled between a pulser and receive circuitry, a capacitor network coupled between a pulser and receive circuitry, and/or a current source couplable to the input terminal of receive circuitry to which a transducer is also couplable. The collapse voltages of transducers may be characterized using BIST circuitry, and a bias voltage may be applied to the membranes of the transducers based at least in part on their collapse voltages. The capacitances of transducers may also be measured using BIST circuitry and a notification may be generated based on the sets of measurements.

The present disclosure discloses a sensing device, comprising a sensor configured to convert a sound signal into an electrical signal, the sensor having a first resonant frequency; and a resonant system including a vibration pickup unit and configured to generate a vibration in response to a vibration of a housing of the sensing device. The vibration pickup unit may include at least an elastic diaphragm and a mass block. The elastic diaphragm may be connected to the housing the sensing device through a peripheral side of the elastic diaphragm. The mass block may be at least made of a polymer material. A first acoustic cavity may be defined between the elastic diaphragm and the sensor. When the housing of the sensing device generates a vibration in response to an external sound signal, the elastic diaphragm and the mass block may generate a vibration in response to the vibration of the housing of the sensing device. The elastic diaphragm may cause a sound pressure change in the first acoustic cavity during a vibration process, and the sensor may convert the external sound signal into an electrical signal based on the sound pressure change in the acoustic cavity. The resonant system may provide at least one second resonant frequency to the sensing device. The second resonant frequency may be lower than the first resonant frequency.

The embodiments of the present disclosure provide a sensor device, including: a sensor assembly with a first resonant frequency and a sound pickup assembly configured to communicate with an external sound of the sensor device through a sound inlet, wherein an acoustic cavity may be formed between the sound pickup assembly and the sensor assembly, when the sound pickup assembly vibrates in response to an air conduction sound transmitted through the sound inlet, vibrations of the sound pickup assembly may change a sound pressure in the acoustic cavity, and the sensor assembly may convert the air conduction sound into an electrical signal based on changes of the sound pressure in the acoustic cavity, wherein the sound pickup assembly may provide the sensor device with a second resonant frequency, and a difference between the second resonant frequency and the first resonant frequency may be in a range of 1000 Hz-10000 Hz.

The present disclosure provides a sensing device, comprising: a housing, an accommodation cavity being provided inside the housing; a transduction unit, including a vibration-pickup structure used to pick up vibration of the housing to generate an electrical signal, wherein the transduction unit divides the accommodation cavity into a front cavity and a rear cavity located on opposite sides of the vibration-pickup structure, at least one of the front cavity or the rear cavity is filled with liquid, and the liquid is in contact with the vibration-pickup structure; and one or more pipeline structures, each pipeline structure being configured to connect the accommodation cavity to an outside of the housing, the liquid being at least partially located in the one or more pipeline structures.

One of the embodiments of the present disclosure provides a sensor device, including: a housing and a transducer unit, wherein the housing has an accommodating cavity inside, the transducer unit includes a vibration pickup structure configured to pick up a vibration of the housing and produce an electrical signal, and the transducer unit in the accommodating cavity separates the accommodating cavity to form a front cavity and a rear cavity on opposite sides of the vibration pickup structure. At least one cavity of the front cavity and the rear cavity is filled with liquid, the liquid is in contact with the vibration pickup structure, and an air cavity is formed between the liquid and the housing.

A sensor device comprises at least one transducer and a sensing material disposed on the transducer. The sensing material adsorbs or absorbs an amount of analyte (e.g., a target gas) that depends on a temperature of the sensing material and a concentration of the analyte. At least one detector is arranged to measure responses of the transducer to sorption or desorption of the analyte in the sensing material while the sensing material is heated and/or cooled according to at least one temperature profile. The device also comprises a humidity sensor that is arranged to detect a humidity level of the environment or sample containing the analyte. A processor or controller is programmed to determine the quantity (e.g., concentration) of the analyte by comparing values of the transducer measurement signals to reference data indicative of expected or pre-measured responses of the transducer to known concentrations of the analyte at the same humidity level as indicated by the humidity sensor while the sensing material is subjected to the same or similar temperature profile.

Micromachined ultrasonic transducers integrated with complementary metal oxide semiconductor (CMOS) substrates are described, as well as methods of fabricating such devices. Fabrication may involve two separate wafer bonding steps. Wafer bonding may be used to fabricate sealed cavities in a substrate. Wafer bonding may also be used to bond the substrate to another substrate, such as a CMOS wafer. At least the second wafer bonding may be performed at a low temperature.