Novel Thin Film Transducers for Durable High-Resolution Imaging in Industry and Medicine

The mass-manufacture of high-resolution ultrasound transducers remains a challenge. This work presents a scalable, additive manufacturing method for producing ultrasound transducers. The thin-film based sensors are easy to assemble, highly customizable, and provide large bandwidth at high frequency. A novel sensor material is deposited on to a flexible substrate using a reactive sputtering method and assembled in to a tightly focused ultrasound transducer. A, B and C-mode data was recorded with a DPR 500 (JSR Electronics), 330V excitation, OdB pre-amplifier gain, 5-300MHz bandwidth by mechanically scanning the transducer. The high frequency thin-film transducer was used to produce images several test objects. The results show that high frequency probes based on thin-film technology could be used in acoustic microscopy for semiconductor and inspection applications. The probes were characterized found that thin film probes can be manufactured to have an average center frequency at 50MHz, with customizable focal point from 6mm up to 12mm.

I. Introduction

Ultrasound has wide range of industrial and biomedical applications, such as medical imaging [1], [2], nondestructive evaluation (NDE)[3], [4], therapeutic ultrasound [5], [6], ultrasonic actuation [7], [8], cell manipulation [9], and acoustic microscopy [10]. Compared to traditional ceramic based, single crystal or piezocomposite probes, probes utilising a thin film sensor element have several advantages: consistent performance, scalability and consistency of manufacturing, and durability. Ceramic, composite or crystal based high frequency probes are fragile because the sensor element needs to be machined to 10s of micrometers thick for sub mm resolution in water.