This papers reports the development of a novel focused optically-transparent ultrasound transducer with wide bandwidth for photoacoustic microscopy (PAM). It consists 9-μm-thick polyvinylidene fluoride (PVDF) film coated Indium-tin oxide (ITO) and metal electrodes, which is laminated onto concave glass lens. A new fabrication process was developed to ensure formation continuous ITO coatings on curved surface without fracturing. Both optical acoustic experiments were conducted characterize...

This Letter reports acoustic-resolution-photoacoustic microscopy (AR-PAM) based on a new optically transparent focused polyvinylidene fluoride (PVDF) transducer with high acoustic numerical aperture (NA) of 0.64. Owing to the improved fabrication process, has much higher NA (0.64) than previously reported low-NA ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">N</mml:mi>...

We report the feasibility study of a new acoustic and optical bi-modal distance & material sensor for robotic grasping. The is designed to be mounted on robot fingertip provide last-moment perception before contact happens. It based both pulse-echo ultrasound optoacoustic effects enabled by single-element air-coupled transducers. In contrast conventional contact-based recent pre-touch approaches, this method overcomes their disadvantages provides fingers with capability detect type target at...

To continuously improve robotic grasping, we are interested in developing a contactless fingertip-mounted sensor for near-distance ranging and material sensing. Previously, demonstrated dual-modal dual sensing mechanisms (DMDSM) pretouch prototype based on pulse-echo ultrasound optoacoustics. However, the complex system, bulky expensive pulser-receiver, omni-directionally sensitive microphone block from practical applications real fingers. address these issues, report second generation (G2)...

To improve robotic grasping, we are interested in developing a new non-contact fingertip-mounted sensor for near-distance ranging and material sensing. Here report progress combining direct pulse-echo ultrasound optoacoustic effects design to deal with optically and/or acoustically challenging targets (OACTs). Our dual-modal dual sensing mechanisms (DMDSM) is enabled by novel wideband transmitter embedded inside piezoelectric (lead zirconate titanate - PZT) ring transducer. The DMDSM capable...

This article reports a new optically transparent focused poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] transducer for photoacoustic microscopy (PAM), which is fabricated by process based on precutting and direct lamination. Compared with the previous fabrication process, it simpler makes possible to achieve high numerical aperture (NA) without stretching (brittle) piezoelectric film. For demonstration, prototype has been 10- <inline-formula...

For improving the quality and profitability of watermelon production, rapid non-destructive detection ripeness is important. Conventional acoustic optical testing methods are based on indirect measurements, which require complex modeling suffer from low accuracy. This article reports initial investigation using photoacoustics (PAs), a hybrid modality light sound, for rind thickness inner flesh redness, two visual hallmarks ripeness. A new low-cost handheld PA probe designed fabricated to...

This paper presents a receiver front-end circuit for wideband high-frequency ultrasound transducer applications. The front end consists of three main blocks, low noise amplifier (LNA), variable gain (VGA) and biquad pass filter (LPF). is specifically designed polyvinylidene fluoride (PVDF) imaging with typical signal bandwidth 10–60 MHz. To achieve both figure (NF) good impedance matching (S11) performance, nonlinearity canceling technique utilized in the LNA. 0.18 µm CMOS technology....

We report the feasibility study of a new optoacoustic sensor for both near-distance ranging and material thickness classification robotic grasping. It is based on effect where focused laser pulses are used to generate wideband ultrasound signals in target. With much smaller optical focal spot, achieves lateral resolution 93 μm, which six times higher than pulse-echo under same condition. A multi-mode PZT (lead zirconate titanate) transducer built properly receive signal. The ability low-...

This paper presents a simultaneous noise and distortion canceling low amplifier (LNA) for high-frequency ultrasound imaging applications. A feedforward technique is developed to achieve both figure (NF) good input impedance matching (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> ). The LNA also exploits the complementary characteristics of NMOS PMOS transistors cancel second-order harmonic linearity enhancement. proposed designed in...

This paper reports the development of dual-modal all-optical photoacoustic microscopy (PAM) and viscoelasticity testing (PAVT) based on a common setup with tunable annular-beam excitation wideband laser-vibrometer detection. For PAM, annular beam is reduced to small diameter excite longitudinal bulk acoustic waves (BAWs) from light-absorbing targets buried in sample, imaging quality improved by specified synthetic aperture focusing technique (SAFT). PAVT, circularly converging surface (SAWs)...

Bioimpedance technology (BMI) is a non-invasive detection that widely applied in volume measurement, human tissue structure analysis and body composition analysis. It uses the electrical characteristics, such as impedance, admittance dielectric constant, changes of biological tissues organs to extract biomedical information about physiological pathological conditions. This paper analyzes influence distribution frequency points on characteristic parameters measurement bio-impedance spectrum....

This article reports the fine-tuning of optical resonance wavelength (ORW) surface-micromachined ultrasound transducer (SMOUT) arrays to enable data readout with non-tunable interrogation light sources for photoacoustic computed tomography (PACT). Permanent ORW tuning is achieved by material deposition onto or subtraction from top diaphragm each element sub-nanometer resolution. For demonstration, a SMOUT array first fabricated, and its tuned an 808 nm laser diode (LD). Experiments are...

Fingertip-mounted pretouch sensors are very useful for robotic grasping. In this paper, we report a new (G3) dual-modal and dual sensing mechanisms (DMDSM) sensor near-distance ranging material sensing, which is based on pulse-echo ultrasound (US) optoacoustics (OA). Different from previously reported versions, the G3 utilizes self-focused US/OA transceiver, thereby eliminating need of bulky parabolic reflective mirror focusing laser beams. The beams can be easily steered by (flat) scanning...

This paper reports the development of a new charge amplification approach for photoacoustic tomography (PAT) based on parallel acoustic delay line (PADL) arrays. By using PADL array to create different time delays, multiple-channel PA signals can be received simultaneously with single-element transducer followed by single-channel DAQ electronics image reconstruction. Unlike conventional voltage amplifiers whose output drops increasing capacitance, both theoretical analysis and experimental...

Latest research clearly demonstrates the excellent capability of gear power skiving technology. For further improvement process and enhancement reliability fundamental on cutting mechanism cylindrical was conducted. First kinematic model mathematical equations cutter were established according to engagement principle crossed helical gears. Then, based proposed model, we investigated simulation process, chip deformation top relief angle. The results support design optimization are an...

Abstract Aiming at the difficulty of manufacturing error detection internal cavity structural parts, a method common based on industrial CT images was proposed. Firstly, image sequence part scanned by an machine is converted into three-dimensional measurement model; Then, registration model with original design completed; The surface information obtained segmenting surfaces Next, datum selected, value test calculated after selecting surface; Finally, result comparing tolerance value,...

Photoacoustic tomography (PAT) is a hybrid imaging technique, which capable of providing abundant optical contrast and high spatial resolution at deep penetration depth. One fundamental challenge in current PAT system design caused by the opaque structure ultrasound transducer arrays, prevents effective light energy delivery onto target. To address this issue, we report new optically-transparent PVDF (polyvinylidene fluoride) array for PAT. It consists 1D 16 elements, each has transparent...

In photoacoustic microscopy (PAM), the ultrasound transducer plays a critical role in detecting PA signals. However, conventional transducers are optically opaque, which could hinder effective delivery of excitation laser onto target. Recently, optically-transparent have been investigated to address this issue. Nevertheless, transparent demonstrated so far either small numerical aperture (NA) or narrow bandwidth, limits their acoustic focal spot sizes and therefore achievable spatial...

This paper presents a wideband low-noise amplifier (LNA) front-end with noise and distortion cancellation for high-frequency ultrasound transducers. The LNA employs resistive shunt-feedback structure feedforward noise-canceling technique to accomplish both impedance matching low performance. A complementary CMOS topology was also developed cancel out the second-order harmonic enhance linearity. (HFUS) photoacoustic (PA) imaging front-end, including proposed variable gain (VGA), designed...

This paper reports a new optically transparent focused P(VDF-TrFE) (poly(vinylidene fluoride-co-trifluoroethylene)) transducer for photoacoustic microscopy (PAM), which is fabricated by process based on pre-cutting and direct-lamination. Compared with the previous fabrication process, it simpler, makes possible to achieve high numerical aperture (NA) without stretching (brittle) piezoelectric film. For demonstration, prototype has been 10-μm-thick 70/30 film laminated onto plano-concave...