Ultrasonic sensors is a technological concept and methodological approach centered on the generation, propagation, and reception of sound waves with frequencies exceeding the human auditory range to acquire information about physical environments, including object detection, distance measurement, and material characterization, based on the analysis of wave interaction phenomena such as reflection, transmission, and absorption. This field investigates the principles of ultrasonic wave behavior and develops sensor systems for non-contact sensing applications across various scientific and engineering domains.