Ultrasound Barrier

Abstract

The packaged micromachined transducer elements are employed in a miniaturized ultrasound barrier. Ultrasound barriers are used for object detection and counting items in industrial environments in which light barriers cannot be applied. The main applications are detection of objects which are transparent or the operation in a dusty and smoky environment. The ultrasound barrier microsystem is formed by two packaged membrane resonators facing each other at distances of up to 150 mm. Figure 6.1 shows a schematic cross-section of the micromachined ultrasound barrier. While the operating principle of the ultrasound barrier is discussed in Section 6.1 , a packaged prototype of the micromachined ultrasound barrier which is currently under test at our partner company Baumer Electric is presented in Section 6.2.