Photoacoustic transmitter represents a promising substitute for conventional piezoelectric counterparts. However, lack of easy and effective method for dynamically manipulating the focused acoustic field is a common and tricky problem faced by current photoacoustic technology. In this paper, a new strategy for constructing focus tunable photoacoustic transmitter is proposed. Different from existed prevailing device architecture, a sandwich like photoacoustic conversion layer is innovatively designed into a suspending elastic membrane with clamped boundary and it can be deformed using integrated pneumatic actuator. Owing to the membrane deflection property, concave spherical contours with variable radius of curvature can be obtained. Considering the shape determined sound emission characteristic, continuous tuning on the axial focusing length of the acoustic field has been successfully demonstrated in the photoacoustic transmitter for the first time. Besides, acoustic signal with significantly improved negative pressure has also been achieved especially at the focus, bringing additional advantage for applications.
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http://dx.doi.org/10.1016/j.pacs.2020.100224 | DOI Listing |
Ultrasonics
March 2024
North Carolina State University, 1804 Entrepreneur Drive, Raleigh, NC 27606, USA. Electronic address:
As the demand for clean energy becomes greater worldwide, there will also be an increasing demand for next generation nuclear power plants that incorporate advanced sensors and monitoring equipment. A major challenge posed by nuclear power plants is that, during normal operation, the reactor compartment is subjected to high operating temperatures and radiation flux. Diagnostic sensors monitoring such structures are also subject to temperatures reaching hundreds of degrees Celsius, which puts them at risk for heat degradation.
View Article and Find Full Text PDFSensors (Basel)
April 2022
Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea.
In this paper we demonstrate strain-dependent photoacoustic (PA) characteristics of free-standing nanocomposite transmitters that are made of carbon nanotubes (CNT) and candle soot nanoparticles (CSNP) with an elastomeric polymer matrix. We analyzed and compared PA output performances of these transmitters which are prepared first on glass substrates and then in a delaminated free-standing form for strain-dependent characterization. This confirms that the nanocomposite transmitters with lower concentration of nanoparticles exhibit more flexible and stretchable property in terms of Young's modulus in a range of 4.
View Article and Find Full Text PDFPhotoacoustics
March 2022
Multimodal Medical Imaging (M3i) group, Technical Medical Centre, University of Twente, Netherlands.
We present a protocol for the design, fabrication and characterisation of laser-induced ultrasound transmitters with a specific, user-defined frequency response for the purpose of ultrasound tomography of large-volume biomedical samples. Using an analytic solution to the photoacoustic equation and measurements of the optical and acoustic properties of the materials used in the transmitters, we arrive at a required mixture of carbon black and polydimethylsiloxane to achieve the desired frequency response. After an in-depth explanation of the fabrication and characterisation approaches we show the performance of the fabricated transmitter, which has a centre frequency of 0.
View Article and Find Full Text PDFPhotoacoustics
March 2021
School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
Photoacoustic transmitter represents a promising substitute for conventional piezoelectric counterparts. However, lack of easy and effective method for dynamically manipulating the focused acoustic field is a common and tricky problem faced by current photoacoustic technology. In this paper, a new strategy for constructing focus tunable photoacoustic transmitter is proposed.
View Article and Find Full Text PDFBiomed Opt Express
March 2021
Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
We demonstrate a laser-generated focused ultrasound (LGFU) transducer using a perforated-photoacoustic (PA) lens and a piezoelectric probe hydrophone suitable for high-frequency ultrasound tissue characterization. The perforated-PA lens employed a centrally located hydrophone to achieve a maximum directional response at 0° from the axial direction of the lens. Under pulsed laser irradiation, the lens produced LGFU pulses with a frequency bandwidth of 6-30 MHz and high-peak pressure amplitudes of up to 46.
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