CMUT-on-CMOS is a high-frequency (1 to 50 MHz) ultrasound technology that enables high-resolution 3D medical imaging and the development of ultra-compact imagers that can be installed in catheters. MEMS is a mature technology that operates using a completely different mechanism than traditional mechanical devices and molecular-sized devices. MEMS devices have been widely distributed in communications, transportation, military, industrial and consumer applications. The technology continues to evolve in emerging applications such as power conversion, virtual worlds, 6G telephony, and advanced medical diagnosis and treatment.