PHOTOACOUSTIC AND ULTROSOUND DUAL-MODALITY ENDOSCOPIC IMAGING BASED ON ALN PMUT ARRAY

This article reports an aluminum nitride(AlN) piezoelectric micromachined ultrasound transducer (PMUT) array enabling dual imaging modality of photoacoustic (PA) and ultrasound (US) endoscopy. AlN is a kind of non-toxic material, making it suitable for biomedical, especially implantable applications. In clinical endoscopic imaging, pulse-echo US signal can distinguish soft tissues' mechanical properties easily, while PA signal is more sensitive to tissues' optical absorption property. Both US and PA signals can be received by fabricated AlN PMUT array. This dual-modal endoscopic imaging provides doctors both structural and functional information for accurate diagnostics. Moreover, the miniature size of MEMS PMUT is highly potential to enable intravascular imaging within 1 mm diameter in the future.