Structural Health Monitoring (SHM) can be seen as a technique inspired by nature. In living organisms, any sort of damage, e.g., a scratch on the skin, is sensed and processed to evaluate the effect and possible actions necessary due to this event. This also applies to an SHM system that is implemented into artificial structures like buildings or vehicles, to achieve the same thing. In this chapter, a short state-of-the-art for SHM in materials, focusing on ultrasonic methods, is provided followed by the theoretical part as a basis for the presented measurements. After that, the wireless sensor node developed in this work is used for embedded measurements of Lamb waves in FML. Measurements on and in plates are done for both, piezoelectric and piezoresistive Lamb wave sensors for the intended application.