3D-Printed SAW Sensor Development for Enabling Remote Monitoring of Advanced Reactors

Abstract

Recent and future advancements in the upcoming digital era of Nuclear Industry would rely heavily on real-time, remote, and unattended monitoring, as well as continuous data collection. Advanced reactor designs (e.g., Microreactors, SMR, etc.) intended for installation in remote and possibly inaccessible locations would require robust, compact, passive, low-cost, radiation-tolerant, and energy efficient sensor systems that could be remotely interrogated and provide real-time information of operating and safety-related parameters (temperature, flux, etc.). In addition, to ensure economic competitiveness and minimize sensor costs, it is equally important to guarantee a simple, streamlined, and cost-efficient manufacturing procedure. To achieve this, we explore the development of low-cost 3D-printed Surface Acoustic Wave (SAW) sensors optimized for remote monitoring of advanced reactors. SAW sensors are passive devices that can convert an electromagnetic wave into a surface acoustic wave propagating along a piezoelectric substrate. The mechanical wave is then reflected and eventually converted back into an electrical signal which can be broadcasted. These characteristics offer unique advantages including sensor simplicity, power-free operation, and radiation tolerance since no integrated circuits are needed. To develop customized SAW sensors, we used a state-of-the-art aerosol jet printer that enables precise fabrication of sensors with features as small as 10 μm. In this work, LiNbO3, LiTaO3 and Quartz substrates are used to demonstrate the feasibility of the proposed approach by 3D-printing two-port SAW structures using conductive silver nanoink. A parametric analysis is performed in order to optimize the printing procedure and investigate optimization of printing line resolution using optical and Scanning Electron Microscopy.