Singh Nagendra, Biswas S K
Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Knowledge City, Sector 81, SAS Nagar, Manauli, 140306, India.
Adv Healthc Mater. 2025 Mar;14(7):e2403711. doi: 10.1002/adhm.202403711. Epub 2025 Jan 28.
Fluoropolymer alone, as an alternative to lead-based piezoelectric materials, has shown multiple challenges to develop useful sensors for solving real-world problems such as photoacoustic, ultrasound pulse echo, and other non-destructive testing. This work demonstrates the fabrication of high frequency and wide bandwidth transducers with fluoropolymer and highly polarizing cubic single crystal Barium titanate (BaTiO) ceramic composite for high resolution in-vivo photo-acoustic and ultrasound imaging. For transducer fabrication, a customized bio-compatible nanocomposite sensor film of PVDF-TrFE (Polyvinylidene fluoride trifluoroethylene)/BaTiO (BTO) is synthesized by drop and dry in heating-cum-electro-poling system for advancing polarization, crystallinity, and higher charge generation. The ratio of nanofiller cubic single crystal BTO and PVDF-TrFE is optimized using characterization techniques such as FTIR, XRD and electrometer. Thereafter, SEM and TGA analyses are performed to study the surface morphology and thermal stability of the sensing film. Transducers with central frequencies varying from 17 to 42MHz are fabricated and tested for both pulse-echo mode and receiving photoacoustic signals. These transducers are used for sensing photoacoustic signals generated from hemoglobin and eumelanin and further for ultrasound and photoacoustic imaging. The imaging results are compared with the results obtained using a commercial ultrasound and photoacoustic imaging device. To the best of the knowledge and available literature, for the first time, the fabrication of ultrasound/photoacoustic transducers with cubic single-crystal nanofiller and fluoropolymer nanocomposite is showed. The detailed transducer fabrication method, characterization results, and imaging of biological tissue using photoacoustic and ultrasound are presented.
仅含氟聚合物作为铅基压电材料的替代品，在开发用于解决诸如光声、超声脉冲回波及其他无损检测等实际问题的实用传感器方面面临诸多挑战。这项工作展示了用氟聚合物和高极化立方单晶钛酸钡（BaTiO₃）陶瓷复合材料制造高频宽带换能器，用于高分辨率体内光声和超声成像。为制造换能器，通过在加热兼电极化系统中滴涂并干燥的方法合成了定制的生物相容性聚偏二氟乙烯 - 三氟乙烯（PVDF-TrFE）/钛酸钡（BTO）纳米复合传感器薄膜，以促进极化、结晶度并产生更高电荷。使用傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）和静电计等表征技术优化纳米填料立方单晶BTO与PVDF-TrFE的比例。此后，进行扫描电子显微镜（SEM）和热重分析（TGA）以研究传感薄膜的表面形态和热稳定性。制造了中心频率在17至42MHz之间变化的换能器，并对其进行脉冲回波模式和接收光声信号的测试。这些换能器用于检测由血红蛋白和真黑素产生的光声信号，并进一步用于超声和光声成像。将成像结果与使用商用超声和光声成像设备获得的结果进行比较。据所知及现有文献，首次展示了用立方单晶纳米填料和氟聚合物纳米复合材料制造超声/光声换能器。本文介绍了详细的换能器制造方法、表征结果以及使用光声和超声对生物组织进行成像的情况。
