Abstract: Capacitive micromachined ultrasonic transducers (CMUTs) in permanent contact mode are provided. Such a CMUT always has its plate in contact with the substrate, even for zero applied electrical bias. This contact is provided by the pressure difference between the environment, and the pressure of the evacuated region between the CMUT plate and substrate. Due to this permanent contact, the electric field in the gap for a given DC bias voltage will be larger, which provides improved coupling efficiency at lower DC bias voltages. Furthermore, in an environment with high and varying pressure, the plate will not shift between the conventional mode and the collapsed mode, but will only be pushed down with varying contact radius. In some embodiments, an electrode shaped as an annulus is employed, so that only the active vibrating part of the CMUT plate sees the applied DC and AC voltages.

Abstract: Ultrasound imaging and therapy with the same array of capacitive micromachined ultrasonic transducers is provided. The electronics includes a per-pixel switch for each transducer element. The switches provide an imaging mode driven completely by on-chip electronics and a therapy mode where off-chip pulsers provide relatively high voltages to the transducer elements.

Abstract: We provide arrays of capacitive micromachined ultrasonic transducer (CMUT) elements having large fractional bandwidth and configured such that each array element operates both to transmit and to receive. Large fractional bandwidth is provided by venting the CMUT cavity, which provides an additional source of damping for the resonant CMUT.

Abstract: A multi-touch ultrasonic touchscreen is provided that includes a solid plate, an ultrasonic transducer disposed on an edge or surface of the solid plate that is capable of transmitting and receiving dispersive acoustic Lamb waves, and an appropriately programmed computer that is capable of operating the ultrasonic transducer to transmit and receive the dispersive acoustic Lamb waves, where the solid plate is capable of reflecting the transmitted dispersive acoustic Lamb waves internally and at edges and corners of the plate in a ubiquitous distribution within the solid plate, where the internal reflections include solid plate top and bottom surface reflections of the dispersive acoustic Lamb waves, where the edge and corner reflections are physical reflection to propagation of the dispersive acoustic Lamb waves, where the appropriately programmed computer is capable of operating on the received Lamb wave to determine an occurrence and location of a touch to the solid plate.

Abstract: Aspects of the present disclosure are directed towards methods, systems, and apparatuses that include a pressure-sensor arrangement including a plate structure and a plurality or array of pressure-sensor cells. Additionally, the methods, systems, and apparatuses include integrated circuitry communicatively coupled to the pressure-sensor arrangement that senses pressure changes exhibited by changes in capacitance or vibrational characteristics.

Abstract: The current invention provides an ultrasound-assisted delivery device, that includes a focused ultrasound transducer having an ultrasound focal point, a real-time imaging device having an imaging focal point, and a therapeutic delivery device, where the transducer and the imaging device are integrated with the delivery device, and the ultrasound focal point coincides with the imaging focal point, where the delivery device and transducer are disposed to provide an unobstructed imaging path for the real-time imaging device. The invention further includes a scanning optical or laser beam having a focal point disposed to sweep across the target, where the delivery device is disposed to deliver an optical contrast material to the target, and the scanning focal point coincides with the ultrasound and imaging focal points, where the target or the optical contrast material react to the scanning beam to generate at least one interface signal.

Abstract: Surface selective photoacoustic (PA) medical imaging is introduced. Surface selective PA imaging is responsive to surface features and does not image sub-surface features, in contrast to conventional PA imaging. The surface PA signal can be considerably larger than the bulk PA signal, for an air-coupled (or gas-coupled) acoustic transducer. Distinguishing these two signals based on time of arrival at the transducer can further distinguish the two signals. This approach provides numerous advantages. Non-contact imaging simplifies and expedites imaging, and can serve as a replacement for visual inspection by physicians. Applications include skin screening and endoscopy.

Abstract: A capacitive micromachined ultrasonic transducer (CMUT) is provided that includes a substrate, a bottom conductive layer disposed on a bottom surface of the substrate, a cavity disposed into a top surface of the substrate, a nonconductive layer disposed on the substrate top surface and on the cavity, a CMUT plate disposed on the nonconductive layer and across the cavity, a top conductive layer disposed on a top surface of the CMUT plate, a pressure control via that spans from the cavity to an ambient environment, and an active pressure controller connected to the pressure control via, wherein the active pressure controller is capable of actively varying a pressure differential across the CMUT plate.

Abstract: As may be implemented in accordance with one or more embodiments, an apparatus and/or method involves a plurality of transducer elements that convert energy waves conveyed via a multi-directional radiation pattern into electrical charge. A power-accumulation circuit accumulates electrical charges from each of the plurality of transducer elements, with each of the transducer elements being arranged at different respective off-axis angles relative to an axis at which the energy is being conveyed. The power-accumulation circuit accumulates energy from each of the individual energy-transduction areas, such that energy received at different respective off-axis angles contributes to the accumulation of electrical charge.

Abstract: A compression post capacitive micromachined ultrasonic transducer (CMUT) is provided. The compression post CMUT includes a first electrode, a top conductive layer having a pattern of post holes, a moveable mass that includes the first electrode. The compression post CMUT further includes an operating gap disposed between the top surface of the top conductive layer and a bottom surface of the moveable mass, a pattern of compression posts, where a proximal end the compression post is connected perpendicularly to a bottom surface of the moveable mass, where the pattern of compression posts span through the pattern of post holes. The top conductive layer includes the second electrode that is electronically insulated from the first electrode, where the pattern of compression posts compress to provide a restoring force in a direction that is normal to the bottom surface of the moveable mass.

Abstract: Low temperature wafer bonding (temperature of 450° C. or less) is employed to fabricate CMUTs on a wafer that already includes active electrical devices. The resulting structures are CMUT arrays integrated with active electronics by a low-temperature wafer bonding process. The use of a low-temperature process preserves the electronics during CMUT fabrication. With this approach, it is not necessary to make compromises in the CMUT or electronics designs, as is typical of the sacrificial release fabrication approach. Various disadvantages of sacrificial release, such as low process control, poor design flexibility, low reproducibility, and reduced performance are avoided with the present approach. With this approach, a CMUT array can be provided with per-cell electrodes connected to the substrate integrated circuitry. This enables complete flexibility in electronically assigning the CMUT cells to CMUT array elements.

Abstract: Surface selective photoacoustic (PA) medical imaging is introduced. Surface selective PA imaging is responsive to surface features and does not image sub-surface features, in contrast to conventional PA imaging. The surface PA signal can be considerably larger than the bulk PA signal, for an air-coupled (or gas-coupled) acoustic transducer. Distinguishing these two signals based on time of arrival at the transducer can further distinguish the two signals. This approach provides numerous advantages. Non-contact imaging simplifies and expedites imaging, and can serve as a replacement for visual inspection by physicians. Applications include skin screening and endoscopy.

Abstract: Focused ultrasound is a promising technology for neural stimulation that is non-invasive, and capable of passing through the skull. Here we use the isolated retina to characterize the effect of ultrasound on an intact neural circuit and compared these effects to those of visual stimulation of the same retinal ganglion cells. Ultrasound stimuli evoked precise, stable responses that looked qualitatively similar to strong visual responses but with shorter latency. We found that ultrasonic stimulation activates cells presynaptic to ganglion cells, which may include photoreceptors and interneurons. Ultrasonic stimulation is an effective and spatial-temporally precise method to activate the retina. Ultrasonic stimulation may have diagnostic potential to probe remaining retinal function in cases of photoreceptor degeneration, and therapeutic potential for use in a retinal prosthesis. In addition, ultrasound promises to be a useful tool to understand the dynamic activity in the interneuron population of the retina.

Abstract: The present invention provides a device that measures at least one property of the liquid or gas, where the invention is a CMUT sensor that includes a substrate, a first layer disposed on the substrate, where the first layer includes a cavity, and a compound plate, where the compound plated includes a bottom plate, an intermediate plate and a top plate. According to the invention, the intermediate plate has at least one sample inlet, a sample cavity and at least one sample outlet, where the bottom plate is disposed on the first layer, and the cavity in the first layer is sealed by the compound plate. The cavity in the first layer can be a vacuum or contain a gas. The CMUT sensor can be disposed in an array of two or more sensors and connected electrically in parallel.

Abstract: An invention for coherent array image formation and restoration is taught. The invention is applicable for both 2D and 3D imaging using either 1D or 2D arrays, respectively. A transducer array is subdivided into subarrays, each subarray having a number of adjacent array elements. All elements of each subarray transmit and receive in parallel. The signals received from each subarray are delayed and summed to form scan lines, or beams. The low-beam-rate beams formed from each subarray are upsampled and interpolated prior to forming high-beam-rate images. Depending on the subarray geometry, a subarray-dependent restoration filter is also applied to the subarray beams. The restored beams from each subarray are combined to form the final high-beam-rate image. The invention significantly reduces the front-end hardware complexity compared to conventional methods such as full phased array imaging with comparable image quality.

Abstract: A compression post capacitive micromachined ultrasonic transducer (CMUT) is provided. The compression post CMUT includes a first electrode, a top conductive layer having a pattern of post holes, a moveable mass that includes the first electrode. The compression post CMUT further includes an operating gap disposed between the top surface of the top conductive layer and a bottom surface of the moveable mass, a pattern of compression posts, where a proximal end the compression post is connected perpendicularly to a bottom surface of the moveable mass, where the pattern of compression posts span through the pattern of post holes. The top conductive layer includes the second electrode that is electronically insulated from the first electrode, where the pattern of compression posts compress to provide a restoring force in a direction that is normal to the bottom surface of the moveable mass.

Abstract: The present invention provides a device that measures at least one property of the liquid or gas, where the invention is a CMUT sensor that includes a substrate, a first layer disposed on the substrate, where the first layer includes a cavity, and a compound plate, where the compound plated includes a bottom plate, an intermediate plate and a top plate. According to the invention, the intermediate plate has at least one sample inlet, a sample cavity and at least one sample outlet, where the bottom plate is disposed on the first layer, and the cavity in the first layer is sealed by the compound plate. The cavity in the first layer can be a vacuum or contain a gas. The CMUT sensor can be disposed in an array of two or more sensors and connected electrically in parallel.

Abstract: A capacitive micromachined ultrasonic transducer (CMUT) array connected to a separate electronic unit is provided. The CMUT array includes at least two active elements, a ground element at the array end, and a non-active element having isolation trenches disposed between the active and ground elements. The active element includes a doped first silicon layer, a doped second silicon layer, and a first insulating layer disposed there between. A cavity is in the first silicon layer having a cross section that includes vertical portions disposed at each end of a horizontal portion, and the vertical portion spans from the first insulating layer through the first silicon layer such that a portion of the first silicon layer is isolated by the first insulating layer and the cavity. A membrane layer on the first silicon layer spans the cavity. A bottom electrode is disposed on the bottom of the second silicon layer.

Abstract: A high temperature micromachined ultrasonic transducer (HTCMUT) is provided. The HTCMUT includes a silicon on insulator (SOI) substrate having a doped first silicon layer, a doped second silicon layer, and a first insulating layer disposed between the first and second silicon layers. A cavity is disposed in the first silicon layer, where a cross section of the cavity includes a horizontal cavity portion on top of vertical cavity portions disposed at each end of the horizontal cavity portion, and the vertical cavity portion spans from the first insulating layer through the first silicon layer, such that a portion of the first silicon layer is isolated by the first insulating layer and the cavity. A membrane layer is disposed on the first silicon layer top surface, and spans across the cavity. A bottom electrode is disposed on the bottom of the second silicon layer.

Abstract: The current invention provides an ultrasound-assisted delivery device, that includes a focused ultrasound transducer having an ultrasound focal point, a real-time imaging device having an imaging focal point, and a therapeutic delivery device, where the transducer and the imaging device are integrated with the delivery device, and the ultrasound focal point coincides with the imaging focal point, where the delivery device and transducer are disposed to provide an unobstructed imaging path for the real-time imaging device. The invention further includes a scanning optical or laser beam having a focal point disposed to sweep across the target, where the delivery device is disposed to deliver an optical contrast material to the target, and the scanning focal point coincides with the ultrasound and imaging focal points, where the target or the optical contrast material react to the scanning beam to generate at least one interface signal.