A thermal excitation acoustic-wave-generating device includes a first acoustic wave source that includes a first heating element and a substrate that includes a main surface along which the first heating element is disposed, a second acoustic wave source that includes a second heating element and a facing body that includes a main surface along which the second heating element is disposed, and a pair of electrodes connected to the first and second heating elements. The first and second acoustic wave sources are arranged such that the first and second heating elements are separated from each other and face each other. The pair of electrodes are disposed between the first and second acoustic wave sources.

Methods, systems, and apparatus for using a two-dimensional distributed mode actuator. One of the systems includes a transducer adapted to create a force to cause vibration of a load to generate sound waves, the transducer having a first width along a first axis; a transfer portion connected to the transducer along a first side parallel to the first axis, and having a second width along the first axis that is less than the first width; and a stub connected to the transfer portion along a second side of the transfer portion that is parallel to the first axis and an opposite side from the first side connected to the transducer, having a third width that is greater than the second width, and having a surface adapted to connect to the load to transfer the force received from the transducer through the transfer portion to the load.

Methods, systems, and apparatus for using a two-dimensional distributed mode actuator. One of the systems includes a transducer adapted to create a force to cause vibration of a load to generate sound waves, the transducer having a first width along a first axis; a transfer portion connected to the transducer along a first side parallel to the first axis, and having a second width along the first axis that is less than the first width; and a stub connected to the transfer portion along a second side of the transfer portion that is parallel to the first axis and an opposite side from the first side connected to the transducer, having a third width that is greater than the second width, and having a surface adapted to connect to the load to transfer the force received from the transducer through the transfer portion to the load.

A method, system and devices to selectively control modal vibrations in an elastic panel with a number of force actuators distributed throughout the surface of the elastic panel to excite/depress the response of one or more vibrational resonant modes included in a prescribed subset. The force actuators are disposed such that prescribed modal excitation/depression may be realized when the actuators are driven by a common source signal.

A method, system and devices to selectively control modal vibrations in an elastic panel with a number of force actuators distributed throughout the surface of the elastic panel to excite/depress the response of one or more vibrational resonant modes included in a prescribed subset. The force actuators are disposed such that prescribed modal excitation/depression may be realized when the actuators are driven by a common source signal.

In at least one embodiment, a multi-stage sound and vibration sensor is provided. The multi-stage sound and vibration sensor includes a housing, a first piezo-diaphragm and a second piezo diaphragm. The first piezo-diaphragm and the second piezo-diaphragm are positioned in the housing to detect an input signal including audio or vibrations. The first piezo-diaphragm and the second piezo-diaphragm provide a first resonance frequency and a second resonance frequency in response to detecting the audio or the vibrations.

An ultra-wide bandwidth acoustic transducer may include multiple layers, including an inner piezoelectric layer, a polymer coupling layer and an outer piezoelectric layer. The polymer layer may be located between, and may be bonded to, the inner and outer piezoelectric layers. The transducer may have multiple eigenfrequencies of vibration. These eigenfrequencies may include primary resonant frequencies of the inner and outer piezoelectric layers respectively and may also include resonant frequencies that arise due to coupling between the layers. An acoustic backscatter system may employ such a transducer in backscatter nodes as well as in a transmitter. The multiple eigenfrequencies may enable the system to perform spread-spectrum communication at a high throughput. These multiple eigenfrequencies may also enable each backscatter node to shift frequency of an uplink signal, which in turn may enable the system to mitigate self-interference and to decode concurrent signals from multiple backscatter nodes.

An ultra-wide bandwidth acoustic transducer may include multiple layers, including an inner piezoelectric layer, a polymer coupling layer and an outer piezoelectric layer. The polymer layer may be located between, and may be bonded to, the inner and outer piezoelectric layers. The transducer may have multiple eigenfrequencies of vibration. These eigenfrequencies may include primary resonant frequencies of the inner and outer piezoelectric layers respectively and may also include resonant frequencies that arise due to coupling between the layers. An acoustic backscatter system may employ such a transducer in backscatter nodes as well as in a transmitter. The multiple eigenfrequencies may enable the system to perform spread-spectrum communication at a high throughput. These multiple eigenfrequencies may also enable each backscatter node to shift frequency of an uplink signal, which in turn may enable the system to mitigate self-interference and to decode concurrent signals from multiple backscatter nodes.

A Micro-Electro-Mechanical System (MEMS) device comprises a piezoelectric transducer having a first frequency behavior, wherein the piezoelectric transducer comprises a piezoelectric trimming region, and control circuitry to provide a bias signal to the piezoelectric trimming region of the piezoelectric transducer for adjusting a second frequency behavior of the piezoelectric transducer.

A Micro-Electro-Mechanical System (MEMS) device comprises a piezoelectric transducer having a first frequency behavior, wherein the piezoelectric transducer comprises a piezoelectric trimming region, and control circuitry to provide a bias signal to the piezoelectric trimming region of the piezoelectric transducer for adjusting a second frequency behavior of the piezoelectric transducer.