Ultrasound covers a broad range of applications from underwater exploration and nondestructive evaluation of materials to medical diagnosis and treatment. The Capacitive Micromachined Ultrasonic Technology CMUT) has emerged as a promising alternative to traditional piezoelectric technology. The fundamental terminology, definitions and concepts related to CMUT are introduced in this research. Three prototypes based on micromachining processes for minimally invasive applications were developed including a multi-looking imager, a miniaturized invasive ultrasonic probe and an image guided therapy...