New Light in Microscopic Exploration: Portable Photoacoustic Microscopy (Invited)

Photoacoustic imaging (PAI), a biomedical imaging mode that combines the high contrast of optical imaging with the deep penetration of ultrasonic imaging, has developed rapidly in recent years. Among them, photoacoustic microscopy ( PAM), as one of the important implementation methods of photoacoustic imaging, can achieve micron-level or even hundreds of nanometer-level resolution on the millimeter imaging depth, and can achieve high-resolution imaging of biological tissue structure, function, and molecules, and has been widely used in clinical diagnosis, skin disease detection, ophthalmology, and other fields. In this paper, the working principle and implementation of PAM are first introduced, and then the research progress of portable PAM technology is reviewed from the handheld and semi- handheld, brain wearable, and integrated multi-mode. Then, the challenges faced by the portable PAM technology are discussed, and finally the prospects are summarized.