Abstract: According to at least one embodiment, a method of fabricating a micro electro-mechanical systems (MEMS) structure is disclosed. The method involves causing an etchant to remove a portion of a sacrificial layer of the MEMS structure, the sacrificial layer between a structural layer of the MEMS structure and a substrate of the MEMS structure. In this embodiment, causing the etchant to remove the portion of the sacrificial layer involves causing a target portion of the substrate to be released from the MEMS structure. According to another embodiment, another method of fabricating a MEMS structure is disclosed. The method involves causing an etchant including water to remove a portion of a sacrificial layer of the MEMS structure, the sacrificial layer between a structural layer of the MEMS structure and a substrate of the MEMS structure. In this embodiment, the sacrificial layer and the substrate are hydrophobic.

Abstract: Methods, systems, and techniques for the contactless operation of capacitive micromachined ultrasonic transducers (CMUTs) and CMUT arrays. Contactless operations refers to both the contactless transfer of energy and information between the transducer(s) and the controlling subsystem. A system includes a CMUT, a first alternating current voltage source, a first inductor electrically coupled to the first voltage source, and a second inductor electrically coupled to the CMUT. The second inductor is physically decoupled from, and positioned to be wirelessly coupled to, the first inductor. A contactless configuration is useful for a wide range of applications, from wearable transducers to high-end ultrasound imaging systems.

Abstract: An apparatus comprising an array of polymer-based capacitive micromachined ultrasonic transducers positioned on a substrate. The substrate may be at least substantially transparent to ionizing radiation, be flexible, and/or have walls positioned thereon to protect the transducers.

Abstract: According to at least one embodiment, a method of fabricating a micro electro-mechanical systems (MEMS) structure is disclosed. The method involves causing an etchant to remove a portion of a sacrificial layer of the MEMS structure, the sacrificial layer between a structural layer of the MEMS structure and a substrate of the MEMS structure. In this embodiment, causing the etchant to remove the portion of the sacrificial layer involves causing a target portion of the substrate to be released from the MEMS structure. According to another embodiment, another method of fabricating a MEMS structure is disclosed. The method involves causing an etchant including water to remove a portion of a sacrificial layer of the MEMS structure, the sacrificial layer between a structural layer of the MEMS structure and a substrate of the MEMS structure. In this embodiment, the sacrificial layer and the substrate are hydrophobic.

Abstract: A method of sensing a pressure applied to a surface comprises monitoring an electrical signal generated by redistribution of mobile ions in a piezoionic layer under the surface. An externally applied local pressure at a portion of the layer induces redistribution of mobile ions in the piezoionic layer. It is determined that the surface is pressured based on detection of the electrical signal. A piezoionic sensor includes a sensing surface; a piezoionic layer disposed under the sensing surface such that an externally applied local pressure on a portion of the sensing surface causes detectable redistribution of mobile ions in the piezoionic layer; and electrodes in contact with the layer, configured to monitor electrical signal generated by the redistribution of mobile ions in the piezoionic layer.

Abstract: Methods and techniques for fabricating layered structures, such as capacitive micromachined ultrasound transducers, as well as the structures themselves. The layered structure has a membrane that includes a polymer-based layer and a top electrode on the polymer-based layer. The membrane is suspended over a closed cavity and may be actuated by applying a voltage between the top electrode and a bottom electrode that may be positioned along or be a bottom of the closed cavity. The layered structure may be fabricated using a wafer bonding process.

Abstract: Methods and techniques for fabricating layered structures, such as capacitive micromachined ultrasound transducers, as well as the structures themselves. The layered structure has a membrane that includes a polymer-based layer and a top electrode on the polymer-based layer. The membrane is suspended over a closed cavity and may be actuated by applying a voltage between the top electrode and a bottom electrode that may be positioned along or be a bottom of the closed cavity. The layered structure may be fabricated using a wafer bonding process.

Abstract: Methods and techniques for fabricating layered structures using surface micromachining are described. A sacrificial layer is deposited on a substrate assembly that functions as a bottom electrode. The sacrificial layer is patterned into a first shape. A first polymer-based layer is deposited on the sacrificial layer. A top electrode is patterned on the first polymer-based layer above the sacrificial layer. A second polymer-based layer is deposited on the top electrode such that the top electrode is between the first and second polymer-based layers. The sacrificial layer is etched away to form a cavity under the top electrode.

Abstract: Methods and techniques for fabricating layered structures, such as capacitive micromachined ultrasound transducers, as well as the structures themselves. The layered structure has a membrane that includes a polymer-based layer and a top electrode on the polymer-based layer. The membrane is suspended over a closed cavity and may be actuated by applying a voltage between the top electrode and a bottom electrode that may be positioned along or be a bottom of the closed cavity. The layered structure may be fabricated using a wafer bonding process.

Abstract: Methods and techniques for fabricating layered structures, such as capacitive micromachined ultrasound transducers, as well as the structures themselves. The layered structure has a membrane that includes a polymer-based layer and a top electrode on the polymer-based layer. The membrane is suspended over a closed cavity and may be actuated by applying a voltage between the top electrode and a bottom electrode that may be positioned along or be a bottom of the closed cavity. The layered structure may be fabricated using a surface micromachining process.

Abstract: Methods and techniques for fabricating layered structures, such as capacitive micromachined ultrasound transducers, as well as the structures themselves. The layered structure has a membrane that includes a polymer-based layer and a top electrode on the polymer-based layer. The membrane is suspended over a closed cavity and may be actuated by applying a voltage between the top electrode and a bottom electrode that may be positioned along or be a bottom of the closed cavity. The layered structure may be fabricated using a wafer bonding process.

Abstract: A method of sensing a pressure applied to a surface comprises monitoring an electrical signal generated by redistribution of mobile ions in a piezoionic layer under the surface. An externally applied local pressure at a portion of the layer induces redistribution of mobile ions in the piezoionic layer. It is determined that the surface is pressured based on detection of the electrical signal. A piezoionic sensor includes a sensing surface; a piezoionic layer disposed under the sensing surface such that an externally applied local pressure on a portion of the sensing surface causes detectable redistribution of mobile ions in the piezoionic layer; and electrodes in contact with the layer, configured to monitor electrical signal generated by the redistribution of mobile ions in the piezoionic layer.

Abstract: The present disclosure is directed at a method and system for shaping a membrane a capacitive micromachined ultrasonic transducer, or CMUT. A bias voltage is asymmetrically applied to a membrane of the CMUT such that the membrane is directed to send ultrasonic waves that propagate along a propagation axis that is not parallel with a propagation axis along which ultrasonic waves propagate when the bias voltage is symmetrically applied to the membrane. In this way, the ultrasonic waves that are generated using a CMUT array can be physically steered to or focused on a target. Steering and focusing ultrasonic waves by altering the shape of the membrane by asymmetrically biasing the membrane reduces grating lobes and can also be used as part of an adaptive control system that can improve ultrasound image quality.