A Focused Optically Transparent PVDF Transducer for Photoacoustic Microscopy
A Focused Optically Transparent PVDF Transducer for Photoacoustic Microscopy
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DOI：
10.1109/jsen.2019.2952971
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发表时间：
2020-03-01
影响因子：
4.3
通讯作者：
Zou, Jun
中科院分区：
文献类型：
--
作者：
Fang, Cheng;Hu, He;Zou, Jun
本文报道了一种用于光声显微镜（PAM）的新型宽带聚焦光学透明超声换能器的研制。它由一个9 μ m厚的聚偏氟乙烯（PVDF）薄膜组成，薄膜上涂有氧化铟锡（ITO）和金属电极，并将其层压在凹面玻璃透镜上。开发了一种新的制造工艺，以确保在弯曲的换能器表面上形成连续的ITO涂层而不会破裂。进行了光学和声学实验来表征换能器的性能。测试结果表明，该换能器的光学透过率为60%（@532 nm），声学中心频率为24 MHz，声学带宽为26 MHz。声学数值孔径（NA）为0.23，可提供0.13 mm的声学焦斑和1.6 mm的焦深。为了演示，建立了一个PAM设置，用于在不同的目标上进行PA成像。与现有的PAM系统相比，光学透明聚焦换能器的使用允许更简单和更紧凑的配置以及更容易对准光学激发和声学焦点。这些特征对于开发用于手持式、可穿戴式甚至内窥镜应用的小型化PAM系统特别有用。
This papers reports the development of a novel focused optically-transparent ultrasound transducer with a wide bandwidth for photoacoustic microscopy (PAM). It consists of a 9-mu m-thick polyvinylidene fluoride (PVDF) film coated with Indium-tin oxide (ITO) and metal electrodes, which is laminated onto a concave glass lens. A new fabrication process was developed to ensure the formation of continuous ITO coatings on the curved transducer surface without fracturing. Both optical and acoustic experiments were conducted to characterize the performance of the transducer. The testing results show that the transducer has an optical transmittance of 60% (@ 532 nm), an acoustic center frequency of 24 MHz, and an acoustic bandwidth of 26 MHz. With an acoustic numerical aperture (NA) of 0.23, it provides a 0.13-mm acoustic focal spot and a 1.6-mm focal depth. For demonstration, a PAM setup was built for conducting PA imaging on different targets. In contrast to existing PAM systems, the use of the optically-transparent focused transducer allows a simpler and more compact configuration and easier alignment of the optical excitation and acoustic focal points. Such features are especially useful for the development of miniaturized PAM systems for handheld, wearable and even endoscopic applications.