Design of Silicon Carbide Surface-Micromachined Capacitive-based Transducers for Non-Destructive Testing Applications

超声波换能器广泛应用于低强度应用，如医学成像、无损检测和测距，或高强度应用，如清洁和液体乳化。几十年来，压电换能器一直是超声波领域的主力。然而，电容式换能器目前正引起人们的极大兴趣。与压电材料相比，其独特的优势在于其较低的机械阻抗，从而提供了与空气等低密度流体介质更好的阻抗匹配的潜力。这种换能器的工作对温度也不太敏感。电容式微加工超声换能器（CMUTs）通常与其接口电路紧密集成，形成完整的独立超紧凑系统。这可以使超声波系统集成到手持设备中。Nabki教授的研究小组开发了一种新型碳化硅CMUT，并展示了一个概念样机，展示了该设备的潜力，并获得了奥林巴斯公司（一家在加拿大拥有许多研发业务的国际公司）的兴趣。奥林巴斯在工业、医疗和消费市场开展业务，专门从事光学、电子和精密工程，产品部署在加拿大和世界各地。值得注意的是，奥林巴斯是世界领先的创新无损检测（NDT）仪器制造商，用于工业和研究应用。该公司在魁北克市拥有约400名员工，主要负责研发和生产。在整个Engage项目中，奥林巴斯计划探索和开发在奥林巴斯传感器内执行超声波无损检测所需的不同CMUT实用参数（电压，最佳频率，设备尺寸等）。将进行无损检测的CMUT设计优化，并计划使用我们之前发布的技术，使用快速原型和制造方法制造原型。原型将进行广泛的测试，并与现有的奥林巴斯NDT超声波传感器进行比较。本项目将培养2名HQP，即1名博士生和1名博士后。

Ultrasonic transducers are seeing widespread use in low-intensity applications such as medical imaging, non-destructive testing and ranging, or in high-intensity ones like cleaning and liquid emulsification. For decades, piezoelectric transducers have been the workhorse in ultrasonics. However, capacitive transducers are currently attracting significant interest. A unique advantage over their piezoelectric counterpart lies in their lower mechanical impedance, offering the potential for a better impedance match with low-density fluidic media such as air. The operation of such transducers is also much less sensitive to temperature. Capacitive micro-machined ultrasonic transducers (CMUTs) are usually integrated closely with their interface electronic circuits forming complete stand-alone ultra-compact systems. This can allow ultrasonic systems to be integrated in handheld devices. The research group of Prof. Nabki has developed a novel Silicon Carbide CMUT, and demonstrated a proof of concept prototype showcasing the device's potential, and gaining the interest of Olympus Corporation, an international company with many R&D operations in Canada. Olympus operates in industrial, medical and consumer markets, and specializes in optics, electronics and precision engineering, with products deployed in Canada and around the world. Notably, Olympus is a world-leading manufacturer of innovative non-destructive testing (NDT) instruments that are used in industrial and research applications. It has a large operation in Quebec City of about 400 people, which handles R & D and production. Throughout this Engage project, Olympus is planning to explore and develop the different CMUT practical parameters (voltages, optimal frequency, device dimensions etc.) needed to perform ultrasonic NDT as done within Olympus sensors. A CMUT design optimisation for NDT will be carried out and a prototype is planned to be fabricated using a fast prototyping and manufacturing approach, using our previously published technology. The prototype will be tested extensively, and compared with existing Olympus NDT ultrasonic sensors. This project will provide training for two HQP, namely one PhD student and one postdoctoral fellow.