Image quality enhancement of PMUT-based photoacoustic imaging

Photoacoustic imaging (PAI) is now a very promising imaging technique that provides image with sufficient depth, good resolution, and optical contrast. A conventional PAI system is relatively expensive and mechanically bulky. The study demonstrated that MEMS PMUT achieves miniaturized ultrasound (US) sensor element (either single element or an array of elements) with superior performance in terms of power consumption, flexibility, broader bandwidth, and sensitivity. This implies that these technologically novel qualities hold promise for the use of PMUT as an acoustic sensor in PAI systems in place of the conventional piezoelectric bulk element-based spherical ultrasound (US) transducer. We report our study on the design and development of MEMS PMUT−(central frequency ~ 1MHz) based PAM−that integrates MEMS technology and imaging technology (specifically, photoacoustic imaging (PAI)). In this work, we present a temporal integration of the signals over a certain number (~20) of pulsed light-induced PA waves against the conventional technique to acquire a single 1D PA signals/data corresponding to one individual optical pulse−induced PA waves. This means to say that the enhancement of imaging performance with the use of PMUT acoustic sensor is associated with a reduction of obtainable temporal resolution, i.e., a trade-off exists. With the applied temporal integration method SNR has been improved ~ 20dB. The preliminary study demonstrates that the integration of PMUT in PA imaging modality holds promise as a future (imaging) technology both for biological studies and their applications.