Ultrasonic Coupling Research Articles

Design of Ceramic Packages for Ultrasonically Coupled Implantable Medical Devices.

Ultrasonic acoustic power transfer is an efficient mechanism for coupling energy to millimeter and sub-millimeter implants in the body. To date, published ultrasonically powered implants have been encapsulated with thin film polymers that are susceptible to well-documented failure modes in vivo, including water penetration and attack by the body. As with all medical implants, packaging with ceramic or metallic materials can reduce water vapor transmission and improve biostability to provide decadal device lifetime. In this paper, we evaluate methods of coupling ultrasonic energy to the interior of ceramic packages. The classic wave approach and modal expansion are used to obtain analytical expressions for ultrasonic transmission through two different package designs and these approaches are validated experimentally. A candidate package design is demonstrated using alumina packages and titanium lids, designed to be acoustically transparent at ultrasonic frequencies. Bulk modes are shown to be more effective at coupling ultrasonic energy to a piezoelectric receiver than flexural modes. Using bulk modes, packaged motes have an overall link efficiency of roughly 10%, compared to 25% for unpackaged motes. Packaging does not have a significant effect on translational misalignment penalties, but does increase angular misalignment penalties. Passive amplitude-modulated backscatter communication is demonstrated. Thin lids enable the use of ultrasonically coupled devices even with package materials of very different acoustic impedance. This work provides an analysis and method for designing packages that enable ultrasonic coupling with implantable medical devices, which could facilitate clinical translation.

State-of-the-Art and Practical Guide to Ultrasonic Transducers for Harsh Environments Including Temperatures above 2120 °F (1000 °C) and Neutron Flux above 1013 n/cm2.

In field applications currently used for health monitoring and nondestructive testing, ultrasonic transducers primarily employ PZT5-H as the piezoelectric element for ultrasound transmission and detection. This material has a Curie–Weiss temperature that limits its use to about 210 °C. Some industrial applications require much higher temperatures, i.e., 1000–1200 °C and possible nuclear radiation up to 1020 n/cm2 when performance is required in a reactor environment. The goal of this paper is the survey and review of piezoelectric elements for use in harsh environments for the ultimate purpose for structural health monitoring (SHM), non-destructive evaluation (NDE) and material characterization (NDMC). The survey comprises the following categories: 1. High-temperature applications with single crystals, thick-film ceramics, and composite ceramics, 2. Radiation-tolerant materials, and 3. Spray-on transducers for harsh-environment applications. In each category the known characteristics are listed, and examples are given of performance in harsh environments. Highlighting some examples, the performance of single-crystal lithium niobate wafers is demonstrated up to 1100 °C. The wafers with the C-direction normal to the wafer plane were mounted on steel cylinders with high-temperature Sauereisen and silver paste wire mountings and tested in air. In another example, the practical use in harsh radiation environments aluminum nitride (AlN) was found to be a good candidate operating well in two different nuclear reactors. The radiation hardness of AlN was evident from the unaltered piezoelectric coefficient after a fast and thermal neutron exposure in a nuclear reactor core (thermal flux = 2.12 × 1013 ncm−2; fast flux 2 (>1.0 MeV) = 4.05 × 1013 ncm−2; gamma dose rate: 1 × 109 r/h; temperature: 400–500 °C). Additionally, some of the high-temperature transducers are shown to be capable of mounting without requiring coupling material. Pulse-echo signal amplitudes (peak-to-peak) for the first two reflections as a function of the temperature for lithium niobate thick-film, spray-on transducers were observed to temperatures of about 900 °C. Guided-wave send-and-receive operation in the 2–4 MHz range was demonstrated on 2–3 mm thick Aluminum (6061) structures for possible field deployable applications where standard ultrasonic coupling media do not survive because of the harsh environment. This approach would benefit steam generators and steam pipes where temperatures are above 210 °C. In summary, there are several promising approaches to ultrasonic transducers for harsh environments and this paper presents a survey based on literature searches and in-house laboratory observations.

Core/shell FeVO4@BiOCl heterojunction as a durable heterogeneous Fenton catalyst for the efficient sonophotocatalytic degradation of p-nitrophenol

In this study, a FeVO4@BiOCl p–n heterojunction with n-type porous FeVO4 nanorods as the core and p-type flower-like BiOCl nanostructures as the shell was successfully prepared by a facile hydrothermal method. The novel heterostructure was investigated as a durable heterogeneous Fenton catalyst for ultrasonic irradiation (US), ultraviolet irradiation (UV) and coupling irradiation systems (US/UV). Characterization of FeVO4@BiOCl core shell heterojunction was conducted by XRD, SEM, EDS elemental mapping, TEM, HRTEM, SAED, FTIR, Raman, BET, PZC, XPS and DRS. Several different experimental parameters, including irradiation time, H2O2 concentration, catalyst amount, initial concentration, and pH value, were optimized. The stability and reusability of the prepared FeVO4@BiOCl core shell heterojunction were evaluated as well. Mineralization experiments were carried out using the optimized parameters. The results showed that FeVO4@BiOCl core shell heterojunction exhibits a superior sonophotocatalytic performance compared to either sonocatalysis or photocatalysis. Moreover, the formation of p-n core@shell nanostructures could significantly increase the pHpzc, and to an excellent stability for the degradation of PNP after six cycles. The remarkable enhancement of the degradation performance of FeVO4@BiOCl core shell heterojunction can be attributed to the unique structure and morphology with a matched energy band structure owing to the internal electric field induced by the p–n junction, a high transfer efficiency and the efficient separation of e−/h+ pairs, resulting in a huge number of reactive species for the degradation of PNP. A plausible mechanism over FeVO4@BiOCl core shell heterojunction for the sonophotocatalytic degradation of PNP is proposed based on a special three-way, i.e. one as a photocatalyst and a two-way Fenton-like mechanism with the dissociation of H2O2. Active species trapping and calculated band gap energy were also discussed.

Confocal laser scanning microscopy, a diagnostic alternative for five pigmented lesions on the face: An observational study.

To describe the confocal laser scanning microscopy (CLSM) features of five different facial hyperpigmentation diseases and to highlight the features that can be used to differentiate between the diseases. Confocal laser scanning microscopy features of skin lesions of 406 patients with different facial hyperpigmentation diseases (chloasma, naevus fusco-caeruleus zygomaticus, naevus of Ota, freckles and Riehl melanosis) were retrospectively analysed. All patients were diagnosed clinically. The features of each layer of the skin in the involved regions and at the junction of the lesion with normal skin were studied, and the characteristic features of each disease were identified. The CLSM probe was applied perpendicular to the skin surface. Scanning was performed with medical ultrasonic coupling agent applied between the adhesive window and skin and between the lens and adhesive window. The skin was scanned layer by layer, and the best cross-sectional images were stored in the computer for analysis. Chloasma lesions showed significantly increased pigment content in the epidermal basal layer and, in some cases, varying degrees of pigment particle deposition in the upper dermis. Naevus fusco-caeruleus zygomaticus and naevus of Ota lesions showed normal epidermal pigment content, with cord-like high-refractive pigment masses scattered in the dermis; cord-like or dendritic melanocytes were seen between collagen fibre bundles in the upper and middle dermis, but no inflammatory cell infiltration was seen. Freckles lesions showed increased numbers of pigment particles in the basal layer, but no abnormal changes in the dermis. Riehl melanosis was characterised by liquefaction degeneration of the basal cells, accompanied by considerable monocyte and melanophage infiltration in the dermal papilla. Used in combination with clinical manifestations, CLSM can be a useful auxiliary method for diagnosis of naevus fusco-caeruleus zygomaticus, naevus of Ota, chloasma, freckles and Riehl melanosis.

Research on Ultrasound Coupled Wireless Energy Transmission in Marine Environment

In recent years, the wireless transmission of electric energy and its application have been successful, and the research of using ultrasonic coupling to transfer electric energy has become possible in theory and practice. Most of the above research is based on the application of ultrasonic and electromagnetic wave in the air to transmit electric energy. Compared with mature solids and gas transmission media, the situation of liquid transmission and conversion media is more complex and relatively difficult. In this paper, the underwater ultrasonic coupled power transmission in ocean environment is studied, and the attenuation of the underwater acoustic coupled power transmission is simulated.

In-situ fabrication of submicron α-Al2O3 particle reinforced AlSi9Cu3 alloy matrix composites by TIG arc process

In this paper, the fabrication of submicron α-Al2O3/Al composites from Al-SiO2 system by tungsten inert gas (TIG) arc processing technology was investigated and the submicron α-Al2O3/AlSi9Cu3 composite was prepared by dilution and ultrasonic electromagnetic coupling treatment. The microstructures, phase analysis and mechanical properties of the composites were characterized by optical microscope (OM), scanning electronic microscopy (SEM), energy dispersive spectrometer (EDS), x-ray diffraction (XRD), tensile and microhardness testing, respectively. The results revealed that the morphologies and distribution of α-Al2O3 and silicon was significantly affected by the TIG arc current. With the optimum current (120 A), the in situ reaction was complete, the substituted Si phase was presented in rod-shape or needle-shape and agglomerated at the α-Al grain boundary to form Al-Si eutectic phase, and the grain refinement of α-Al phase was the most obvious. The average size of generated α-Al2O3 particles was about 500 nm, while these particles mainly distributed uniformly along the α-Al grain boundary. Ultrasonic and electromagnetic treatments could promote the uniform distribution of α-Al2O3 particles in the AlSi9Cu3 matrix, while these particles could affect the formation of α-Al dendrites and decrease the secondary dendrite arm spacing from 19.8μm to 10.4 μm. The tensile strength, elongation, and microhardness of the α-Al2O3/AlSi9Cu3 composite with 5vol % particles yielded 282 MPa, 5.8%, and 127HV, respectively. Compared with those of the matrix alloy, they increased 17.9%, 23.4%, and 45%, respectively.

Grease-like coupling agent based on metal ionization method for low-frequency ultrasonic NDT

Abstract In long-distance NDT based on ultrasonic guided waves with low-frequency excitation, the most commonly used industrial coupling agents are grease-like coupling agents. However, these agents show the poor performance in NDT, because they can cause more acoustic energy loss and lower acoustic transmissivity. In the study, to improve the acoustic transmission property of grease-like coupling agents, a new method was proposed to combine different metal ions like Li+, Na+ and Ca2+ with base grease, thus forming new grease-like coupling agents. By comparing with the ultrasonic transmitting property of the regular coupling agents, selects a premium ultrasonic grease-like coupling agent. In the experimental results, when low-frequency ultrasonic guided waves transmitted through the lithium-based coupling agent, except the slight delay of peak response time, pulse signals showed the higher energy transmission efficiency with the better pulse vibration waveforms in the iron medium than other oil-based coupling agents. The newly developed grease-like coupling agent can be easily prepared at a lower cost. Importantly, the new coupling agent can improve the energy transmission performance and greatly enhance the sensitivity of ultrasonic flaw detection.

Preferential directional coupling to ultrasonic sensor using adhesive tape

For structural health monitoring applications, recent studies have demonstrated an increased ultrasonic detection sensitivity of fiber Bragg grating (FBG) sensors through remote bonding of the FBG to a structure. In this case, the S0 or A0 Lamb waves in a structure are coupled to guided L01 waves in an optical fiber at the adhesive bond location, resulting in L01 modes of equal amplitudes propagating in both directions along the optical fiber. We demonstrate that when the adhesive bond is replaced with adhesive tape the S0 mode couples to the same L01 modes, however, with a preferential direction. Therefore, our study investigates the mechanism causing the preferential direction. We first identify different ultrasonic coupling pathways from a plate to an FBG through adhesive tape, demonstrating that both direct and indirect pathways are active, but that the indirect pathway produces the directional coupling. Then we test different adhesive tape parameters through experiments and simulations, demonstrating that flexural rigidity and bond length are parameters that can be used to control the directionality. The results of this work could be applied to design multiplexed FBG sensor arrays with specified signal pathways through the optical fiber networks.

Nanoscale Wetting and Energy Transmission at Solid/Liquid Interfaces.

Understanding the effects and limitations of solid/liquid interfaces on energy transport is crucial to applications ranging from nanoscale thermal engineering to chemical synthesis. Until now, the majority of experimental evidence regarding solid/liquid interactions has been limited to macroscale observations and experiments. The lack of experimental works exploring nanoscale solid/liquid interactions has been accentuated as the body of knowledge from theory and simulations at these scales has exploded in recent years. In this study, we expand on current nanoscale thermal measurement techniques in order to more fully understand solid/liquid interfacial energy transport. We use thermal ablation threshold measurements on thick Au films in various liquids as a metric to describe thermal transport at the Au/liquid interface. Furthermore, using ultrafast pump-probe experiments, we gain insight into this transport through picosecond ultrasonic coupling at solid/liquid interfaces with known macroscopic observations. We find significant variations in both the ablation threshold and the damping of the acoustic modes within the Au films depending on nanoscopic interactions at the solid/liquid interface rather than typical macroscale metrics such as acoustic mismatch, measured contact angle, and work of adhesion.

An ultrasonic-assisted soft abrasive flow processing method for mold structured surfaces

As a fluid-based precise processing method, soft abrasive flow processing has been widely used in advanced electromechanical systems, complex mold manufacturing, and other engineering fields. Because of the low volume fraction of abrasive particles and micro-force/cutting removal characteristics, there exists a potential improvement in terms of processing efficiency and uniformity. In view of the above problems, this article presents an ultrasonic-assisted soft abrasive flow processing method. Based on the realizable k–ε turbulence model and the mixture flow model, an ultrasonic coupling enhancement dynamic model for soft abrasive flow is set up, and the kinetic energy transport equation of realizable k–ε turbulence model can be revised. Using particle image velocimetry technology, an on-line observation experimental platform for ultrasonic-assisted soft abrasive flow is developed to conduct the real-time acquisition of abrasive flow state and particle distribution in a constrained flow passage. An ultrasonic-assisted soft abrasive flow processing experimental platform is established to complete the processing experiment. The experimental results show that the ultrasonic excitation vibration can effectively enhance the turbulence intensity and distribution uniformity of the abrasive flow, the average processing time can be shortened by more than 6 h, and a better surface quality can be obtained.

Investigation of the composite strength of hybrid steel-steel semi-finished products manufactured by laser beam welding and friction welding

An ever-increasing demand for more effective products with lower weight, more compact design and extended functionality has led to the use of material combinations with locally adapted properties instead of mono-materials. The Collaborative Research Centre (CRC) 1153 “Tailored Forming” at LUH addresses this topic with the aim to develop hybrid bulk-metal components on the basis of a new, tailored production process using joined semi-finished products. In contrast to existing manufacturing processes for hybrid bulk-metal components where the joining takes place during the forming process or at the end of the production chain, CRC 1153 uses tailor-made semi-finished products which are joined before the forming process. This contribution focuses on the production of hybrid semi-finished products from a steel-steel (C22.8 and 41Cr4) material combination by means of laser beam as well as friction welding. The effects of additional ultrasonic coupling into the weld-pool are presented for laser beam joining and a positive effect on the weld pool was observed. Furthermore, the resulting properties of the joining zone are investigated by uniaxial tensile tests at room temperature and metallographic analyses of the respective manufacturing processes. The friction welding proved to be a very robust process for the production of semi-finished steel-steel products.

Coupling Ultrasound to the Electro‐Oxidation of Methyl Paraben Synthetic Wastewater: Effect of Frequency and Supporting Electrolyte

AbstractIn this paper, electrooxidation of methyl paraben (MeP) is studied by electrolysis only and electrolysis coupled with sonolysis, using a diamond electrode. Complete mineralization of MeP was achieved for both processes, in chloride and sulfate media. Results showed that, although the oxidation of pollutant is faster in the presence of chloride, the mineralization is favored in sulfate medium. Ultrasound irradiation enhanced the removal of organic matter due to the activation of oxidant species in both supporting electrolytes. Moreover, the formation of chlorine gas in the chloride containing medium improves the ultrasound cavitation effect, promoting faster depletion of the total organic carbon in the first hour of treatment. Regarding the formation of more toxic products, all possible organochlorinated intermediates were removed, since complete mineralization was attained in less than 5 hours. Ultrasonic coupling to the electrolysis process accelerates the destruction of the intermediates and delays the formation of perchlorate, which only begins after the complete removal of the total organic carbon. Low and high ultrasound frequencies were evaluated and were found to produce different effects of cavitation, which affect the electrolysis in different ways. The final result will be a balance between these effects and thus, an optimum frequency can be established for different systems.

Ultrasonic assisted large diameter PBX substitute composites compaction and its mechanical properties

The rates of densification and density uniformity are a key performance of PBX parts. Based on ultrasonic vibration technology, this paper designs and manufactures an upper and lower 20 kHz longitudinal and radial vibration assisted molding system with a 200 mm diameter compacting part at the center axis. In this work, PBX substitute composite was successfully fabricated by pressing of powder with ultrasonic vibration and the influence of ultrasonic vibration force coupling on the mechanical properties of PBX substitute powder was investigated. Applying ultrasonic vibration to result in great rates of densification and higher efficiency of the process is expected. The effects of particle size and vibration amplitude and pressure and weight on the densification behavior and of PBX substitute powder are discussed. The results show that applying ultrasonic vibration leads to a higher relative density and an improved homogeneity, and the growth of the size of the pressed sample can be reduced with the ultrasonic vibration and the larger of static pressure, the smaller of the pressed sample size change. In addition, ultrasonic vibration has a great effect on the finer particles and the surface temperature of the sample is not obviously increased with ultrasonic vibration.

Electrochemical mechanism of tin membrane electrodeposition under ultrasonic waves

Tin was electrodeposited from chloride solutions using a membrane cell under ultrasonic waves. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CHR), and chronopotentiometry were applied to investigate the electrochemical mechanism of tin electrodeposition under ultrasonic field. Chronoamperometry curves showed that the initial process of tin electrodeposition followed the diffusion controlled three-dimensional nucleation and grain growth mechanism. The analysis of the cyclic voltammetry and linear sweep voltammetry diagrams showed that the application of ultrasound can change the tin membrane electro-deposition reaction from diffusion to electrochemical control, and the optimum parameters for tin electrodeposition were H+ concentration 3.5 mol·L−1, temperature 35 °C and ultrasonic power 100 W. The coupling ultrasonic field played a role in refining the grain in this process. The growth of tin crystals showed no orientation preferential, and the tin deposition showed a tendency to form a regular network structure after ultrasonic coupling. While in the absence of ultrasonic coupling, the growth of tin crystals has a high preferential orientation, and the tin deposition showed a tendency to form tin whiskers. Ultrasonic coupling was more favorable for obtaining a more compact and smoother cathode tin layer.

Ultrasonic Investigations on Polonides of Ba, Ca, and Pb

Abstract The temperature-dependent mechanical and ultrasonic properties of barium, calcium, and lead polonides (BaPo, CaPo, and PbPo) were investigated in the temperature range 100–300 K. The second- and third-order elastic constants (SOECs and TOECs) were computed using Coulomb and Born-Mayer potential and these in turn have been used to estimate other secondary elastic properties such as strength, anisotropy, microhardness, etc. The theoretical approach followed the prediction that BaPo, CaPo, and PbPo are brittle in nature. PbPo is found to be the hardest amongst the chosen compounds. Further the SOECs and TOECs are applied to determine ultrasonic velocities, Debye temperature, and acoustic coupling constants along <100>, <110>, and <111> orientations at room temperature. Additionally thermal conductivity has been computed using Morelli and Slack’s approach along different crystallographic directions at room temperature. Finally ultrasonic attenuation due to phonon–phonon interaction and thermoelastic relaxation mechanisms has been computed for BaPo, CaPo, and PbPo. The behaviour of these compounds is similar to that of semi-metals with thermal relaxation time of the order 10−11 s. The present computation study is reasonably in agreement with the available theoretical data for the similar type of materials.

Bi-directional ultrasonic wave coupling to FBGs in continuously bonded optical fiber sensing.

Fiber Bragg grating (FBG) sensors are typically spot-bonded onto the surface of a structure to detect ultrasonic waves in laboratory demonstrations. However, to protect the rest of the optical fiber from any environmental damage during real applications, bonding the entire length of fiber, called continuous bonding, is commonly done. In this paper, we investigate the impact of continuously bonding FBGs on the measured Lamb wave signal. In theory, the ultrasonic wave signal can bi-directionally transfer between the optical fiber and the plate at any adhered location, which could potentially produce output signal distortion for the continuous bonding case. Therefore, an experiment is performed to investigate the plate-to-fiber and fiber-to-plate signal transfer, from which the signal coupling coefficient of each case is theoretically estimated based on the experimental data. We demonstrate that the two coupling coefficients are comparable, with the plate-to-fiber case approximately 19% larger than the fiber-to-plate case. Finally, the signal waveform and arrival time of the output FBG responses are compared between the continuous and spot bonding cases. The results indicate that the resulting Lamb wave signal output is only that directly detected at the FBG location; however, a slight difference in signal waveform is observed between the two bonding configurations. This paper demonstrates the practicality of using continuously bonded FBGs for ultrasonic wave detection in structural health monitoring (SHM) applications.

Ultrasonic assisted microwave synthesis of poly (Chitosan-co-gelatin)/polyvinyl pyrrolidone IPN hydrogel

The hydrogels based on gelatin cross-linked with chitosan (CS) and polyvinyl pyrrolidone (PVP) were synthesized using microwave and ultrasonic coupling technique in this study. This interpenetrating polymer network (IPN) hydrogels were cross-linked by glutaraldehyde and 1,2-Epoxy-4-vinylcyclohexane. The presence of function groups in the structure of hydrogel films were confirmed using Fourier transform infrared spectroscopy (FT-IR), thermal stability was measured by DSC, and the swelling behaviors were measured gravimetrically in distilled water at the temperature of 27°C. At last, the mechanical properties were tested. The results showed that the hydrogel prepared with microwave and ultrasonic exhibited the highest tensile strength (86.68MPa), comparing with the hydrogel prepared with traditional method and only microwave reactive field. The FT-IR and XRD results showed that the chemical reactions occurred between the NH2 of chitosan and the COOH of gelatin, and the introduction of ultrasound can improve the reaction rate. The hydrogel film gained in microwave and ultrasonic coupling field has the best combination properties. Therefore, the new microwave-ultrasonic coupling technique is the potential technology to prepare the new hydrogel due to less synthesis time.

Application of weak ultrasonic treatment on sludge electro-osmosis dewatering

ABSTRACTUltrasonic treatment is a good method of facilitating sewage sludge dewatering characteristics. It can also promote the potential of sludge electro-osmosis dewatering (EDW), which is an accepted method of deep dewatering, but the treatment method and optimizing conditions should be determined by performing experiments. In this study, we consider two treating methods: ultrasonic pre-treatment, which uses ultrasonic treatment as sludge pre-treatment before electro-osmosis dehydration, and ultrasonic coupling, which uses ultrasonic and electric fields simultaneously. Using sludge from the Tianjin Jizhuangzi sewage treatment plant, we analyze the influence of ultrasonic intensity and treatment time on sludge dewatering by performing two different methods. The results show that they effectively facilitated sludge EDW. Under the same conditions, i.e. 2 cm cake initial thickness, voltage of 60 V for 5 min, and 0.1 MPa mechanical pressure for 5.5 min, the optimum processing conditions for ultrasonic pre-treatment were found to be 0.510 W/cm2 and 3.5 min, the dehydration rate reached 34.71%, and the optimum conditions for ultrasonic coupling were 0.255 W/cm2 and 3.5 min, while the dehydration rate reached 40.78%. The dehydration rates for both approaches were clearly better than 17.40%, which was obtained under pure electro-osmosis dehydration. To compare the effects of ultrasonic pre-treatment and ultrasonic coupling on the electro-osmosis dehydration process, in this paper, we present the curves of dehydration rate, electric current, electro-osmosis flow, and scanning electron microscopy for dewatered sludge. Compared with the ultrasonic pre-treatment method, the effect of ultrasonic coupling on electro-osmosis dehydration was more obvious.

Titanate-Based Surface Modification of Paper Waste Particles and its Impact on Rigid Polyurethane Foam Properties

Producing particulate filled polymer composites, even dispersion and sufficient adhesion between filler and polymer matrix is of great importance. In order to solve these issues, methodologies, such as ultrasonic dispersing and coupling agents, are proposed. The impact of particle surface modification with three different titanate coupling agents having the tradenames of TCA L44, TCA L38 and TCA K44 on paper waste sludge particles surface, polyurethane foam composite density, compressive and tensile strengths as well as water absorption and water vapour permeability is evaluated. Apparently, titanates form layer on the particle surface, thus increasing the interfacial adhesion between particles and polymer matrix. Basing on the obtained results, the optimal amount and type of titanate is 1 wt.% of TCA K44.

An Incorporate Ultrasonic Coupling Device for Long-Focal- Zone Photoacoustic Imaging System

An incorporate ultrasonic coupling device for extended focal zone focused photoacoustic imaging was designed. Phantom experimental imaging was carried out. The results show that, with the incorporate ultrasonic coupling device,accurate imaging position of absorber in the sample can be achieved. And it is worth mentioning that without the large water tank,the photoacoustic imaging experimental system become simple. Our work has a potential application in the noninvasive photoacoustic imaging of bio-tissue.