Polyvinylidene fluoride (PVDF), a material with ferroelectric characteristics, is still extremely topical for the manufacturing of transducers, and different examples, some of which have been actively commercialized since the 1980s, are reported in the literature. In this work, we present a review focused on the PVDF technology for the manufacturing of in-air ultrasonic transducers, which found application in medical robotics, sonar systems, and automation industry (e.g., proximity sensors and obstacle detection). The aim is to provide a comprehensive view on the development of such ultrasonic transducers, highlighting the constructive choices and the advantages/disadvantages in a thorough and concise way.

中文翻译：

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用于空中应用的 PVDF 超声波传感器：综述

聚偏二氟乙烯 (PVDF) 是一种具有铁电特性的材料，在制造换能器方面仍然非常热门，文献中报道了不同的​​例子，其中一些自 1980 年代以来已被积极商业化。在这项工作中，我们对用于制造空中超声换能器的 PVDF 技术进行了综述，该技术在医疗机器人、声纳系统和自动化行业（例如，接近传感器和障碍物检测）中得到了应用。目的是提供有关此类超声换能器发展的全面视图，以彻底和简洁的方式突出建设性选择和优缺点。