Research has been conducted on cantilever beam-based piezoelectric micromachined ultrasonic transducers, with a focus on post processing soft interconnecting strategies for in-air rangefinding. The topic appears to be related to broader studies on piezoelectric micromachined ultrasonic transducers (PMUTs) and their applications in various fields, including flowmeters, speakers, and sensors. The specific details and outcomes of the research are not clear from the available information.