Micromachining of ultrasonic transducers can provide large arrays of single cells with accurate dimension control and reliable interconnections on wafer-level. Especially in fluid mediums, silicon-based ultrasonic transducers possess high transduction efficiency. With these advantages both in fabrication and device properties, a wide range of applications are possible. Depending on the size of the ultrasonic cells, they are also applicable for pressure sensing. The multifunctional MEMS device contains four cell arrays that can be actuated separately and used for pressure sensing, ultrasound sending, ultrasound receiving or any combination. In addition, a platinum-based resistive temperature sensor is integrated.