Photoacoustic Characterization of Custom-Made thin Film A1N MEMS Ultrasound Transducers

Abstract

Two MEMS thin film aluminium nitride ultrasound transducer array designs for photoacoustic sensing applications are presented. They are characterized using the pitch and catch technique and photoacoustic excitation. The results of both approaches are subsequently compared.

Miniaturisation of Photoacoustic Sensing Systems Using MEMS Transducer Arrays and MEMS Scanning Mirrors

“…To measure its acoustic response, the MEMS transducer was characterised using photoacoustic excitation [12]. Here a commercial Nd:YAG laser (Brilliant B, Quantel), frequency doubled at 532 nm with 10 ns pulses, a pulse repetition frequency of 10 Hz, pulse energies of 2.2 mJ is focussed to a focal spot size of 250 µm using a 35 mm lens onto an 8% (m/m) gelatine phantom.…”

Application of MEMS Enabled Excitation and Detection Schemes to Photoacoustic Imaging

“…The paper also builds on the utilization of cost-effective, custom-built, thin-film aluminium nitride (AlN) PMUT arrays applied to photoacoustic scanning. While previous work used a 10 Hz PRF commercial Nd:YAG laser as the pulsed light source [15], here we use the MEMS laser as excitation source.…”