A wearable device can include a wearable band configured to contact a user of the wearable device, an actuator, a sensor, and one or more processors in communication with the actuator and the sensor. The processors can be configured to measure a back electromotive force (“EMF”) of the actuator; determine, based on the measured back EMF, data that describes a contact force between the wearable band and the user; and determine, based on the data that describes the contact force, a quality metric describing a data quality of sensor data collected by the sensor. In some embodiments, the processor(s) can determine, generate sensor output data based on the sensor data and based at least in part on the data describing the contact force between the wearable band and the user. For example, one or more machine-learned models maybe leveraged to generate sensor output data that is compensated for the wearable band being too tight or too loose.

Disclosed is a multi-silicon on insulator (SOI) micromachined ultrasonic transducer (MUT) device. The device comprises a multi-SOI substrate and a MUT. The MUT is affixed to a surface of the multi-SOI substrate. The multi-SOI substrate has a first SOI layer and at least a second SOI layer disposed above the first SOI layer. The first SOI layer and the second SOI layer each comprise an insulating layer and a semiconducting layer. The first SOI layer further defines a cavity located under a membrane of a MUT and one or more trenches at least partially around a perimeter of the cavity.

Acoustic medium of ultrasonic grip system consists of piezoelectric generator (1), wheel knuckle (9), ball bearing (10), wheel hub (11), wheel rim (15) and tyre of motor-car (20). The piezoelectric generator (1) creates ultrasound vibrations which are transferred through the acoustic medium to the surface of tyre (17). The ultrasound vibration on the surface of tyre (17) results in the separation of the surface of tyre (17) from the liquid (18) that may be found on tarmac (19) during the rain, which results in the fact that despite the unfavourable weather conditions the motor-car has an optimum rolling surface of tarmac. Also, the vibrations on the surface of tyre (17) in interaction with micro texture of tarmac increases the contact surface of tyre with tarmac, which results in the increase of coefficient of friction, higher grip of tyre and reduction of braking distance of motor-car. The ultrasonic grip system is activated at sudden braking, resp. activation of ABS system. Also, the system is activated on the occasion of activating the ESP and ASR system.

Acoustic medium of ultrasonic grip system consists of piezoelectric generator (1), wheel knuckle (9), ball bearing (10), wheel hub (11), wheel rim (15) and tyre of motor-car (20). The piezoelectric generator (1) creates ultrasound vibrations which are transferred through the acoustic medium to the surface of tyre (17). The ultrasound vibration on the surface of tyre (17) results in the separation of the surface of tyre (17) from the liquid (18) that may be found on tarmac (19) during the rain, which results in the fact that despite the unfavourable weather conditions the motor-car has an optimum rolling surface of tarmac. Also, the vibrations on the surface of tyre (17) in interaction with micro texture of tarmac increases the contact surface of tyre with tarmac, which results in the increase of coefficient of friction, higher grip of tyre and reduction of braking distance of motor-car. The ultrasonic grip system is activated at sudden braking, resp. activation of ABS system. Also, the system is activated on the occasion of activating the ESP and ASR system.

A wearable element is disclosed. In an embodiment a wearable element includes at least one piezoelectric element configured to vibrate so that a haptic impression of an acoustic signal is generated, wherein the wearable element is wearable on a body.

The present disclosure provides a device and a method for reducing and homogenizing residual stress during machining in which a workpiece is fixed, such as milling, boring, drilling and planning, with which high-energy acoustic waves are emitted to the workpiece via a tight contact between a plurality of high-energy wave exciters on a bench and a workpiece coated with a coupling medium, and residual stress inside the machined workpiece is reduced and homogenized through elastic wave energy generated in the workpiece by the high-energy acoustic waves. In this way, the purpose of reducing and homogenizing the residual stress while machining is achieved, realizing a stress-free machining, and the deformation of the workpiece during and after machining is minimized.

A high frequency ultrasound array having a number of transducer elements that are formed in sheet of piezoelectric material. A frame having a coefficient of thermal expansion similar to that of the piezoelectric material surrounds the piezoelectric material and is separated from the piezoelectric material by an epoxy material. Kerf cuts that define the individual elements in the sheet of piezoelectric material extend across a full width of the sheet. In some embodiments, sub-dice kerf cuts that divide a single transducer element into two or more sub-elements also extend all the way across the width of the sheet. A lens positioned in front of the transducer elements can have a radius machined therein to focus ultrasound signals. The frame, transducer elements and lens are bent or curved with the desired radius to focus ultrasound signals.

A pseudo-piezoelectric d33 device includes a nano-gap, and a pair of integral and substantially parallel electrodes having a first sensing electrode and a second sensing electrode. The first sensing electrode and the second sensing electrode constitute a receiver. The nano-gap is disposed between the first sensing electrode and the second sensing electrode. An initial height of the nano-gap is smaller than or equal to 100 nanometers. The nano-gap is formed after a thermal reaction between a semiconductor material and a metal material to form a semiconductor-metal compound. The first sensing electrode of the receiver includes the semiconductor-metal compound to provide an integral capacitive sensing electrode to sense a capacitance change with the second sensing electrode and generate a sensing signal.

Described herein are methods and systems for testing transducers and associated integrated circuits. In some cases, a method or system described herein can comprise modulating a bias voltage using a test signal in order to produce a modulated bias voltage signal useful in testing a plurality of transducers of a transducer array in parallel.

A device (100) for the excitation of a fiber (150) comprises a first piezo bender actuator (110) and a second piezo bender actuator (120). The device (100) also comprises a connection part (130) which is arranged between the first piezo bender actuator (110) and the second piezo bender actuator (120). The device (100) also comprises a movable fiber (150) which is mounted to the connection part (130).