Surgery and Therapy with Power Ultrasonics Devices made with Lead-Free Materials

在超声波装置中，压电材料是超声波的主要来源。在治疗和外科应用中使用的超声波设备中，最常用的压电材料是锆钛酸铅(PZT)，这是一种铅基压电陶瓷。然而，由于铅对人类健康和环境的不利影响，以及与其在电子和医疗设备中的使用相关的健康和安全法规，对无铅压电材料的需求越来越大，功率超声器件的性能取决于设计过程中采用的压电材料的弹性、压电和介电常数(EPD)。此外，由这些常量填充的EPD矩阵是设备设计中使用的有限元建模的重要输入。因此，获得新型无铅压电材料的全部弹性、压电常数和介电常数对于评估其用于治疗和手术的功率超声装置的性能是至关重要的。总体目标是由FUSE CDT和Meggitt A/S合作，通过将有限元分析与新开发的无铅压电材料的全面表征相结合，提出新的功率超声器件设计。为了达到这一目的，将使用一种结合传统表征技术和有限元模型优化算法的方法来获得一系列无铅材料的EPD常数。这项研究将探索如何通过提出新的换能器配置来优化无铅材料的这些特性在功率超声设备中的应用。

In ultrasonic devices, the piezoelectric material is the principal source of ultrasound. In ultrasonic devices used in therapeutic and surgical applications, the most commonly used piezoelectric material is lead zirconate titanate (PZT), a lead-based piezoelectric ceramic. However, due to the adverse effect of lead on human health and the environment, as well as the health and safety legislation relating to its use in electronic and medical devices, there is an increasing demand for lead-free piezoelectric materials.The performance of power ultrasonic devices is reliant on the elastic, piezoelectric and dielectric (EPD) constants of the piezoelectric material adopted in the design process. Also, the EPD matrices, populated by these constants, are vital inputs for finite element modelling used in the design of devices. Hence, it is essential to obtain the full elastic, piezoelectric and dielectric constants of new lead-free piezoelectric materials in order to evaluate their properties for use in power ultrasonic devices for therapy and surgery. The overall aim, a collaboration between FUSE CDT and Meggitt A/S, is to propose novel power ultrasonic device designs by combining finite element analysis with the full characterisation of newly developed lead-free piezoelectric materials. To achieve this aim, a method which combines conventional characterisation techniques with a finite element model optimisation algorithm will be used to obtain the EPD constants for a range of lead-free materials. The research will investigate how these properties of the lead-free materials can be optimally employed in power ultrasonic devices through proposing novel transducer configurations.