Ultrasound is a versatile technology that is becoming increasingly important in medical technology even beyond the established field of imaging. Especially during surgical procedures, the power of sound waves can be used to perform so-called incisionless surgeries. Piezoelectric transducers serve this purpose perfectly: Placed extracorporeal, they project an ultrasonic focus into the body. By absorbing the acoustic energy generated by the sound waves, tissue areas can be manipulated in a targeted manner, e.g. to destroy cancerous tumors or to enhance contactless drug delivery in a minimally invasive manner. Another field of application is the integration of smallest piezo components in catheters for the gentle treatment of deposits in blood vessels or for catheter ablation.