Phononic Crystals and Metamaterials – Promising New Sensor Platforms

Phononic crystals and metamaterials are artificial structures designed for the control of phonon propagation. The ability to magnify the interaction of acoustic waves with matter through specific geometries that are capable of concentrating acoustic waves in a confined volume forms the basis for a novel type of sensor. Label-free biosensors are expected to be the most attractive application. The characteristic feature of phononic crystal sensors are linear or point cavities which act both as efficient acoustic resonator and as microfluidic channel, measurement cell or reactor. In some sense phononic sensors follow the route of photonic crystal sensors. However, there are distinct differences in the physical background. First of all they may give access to volumetric mechanical properties which are linked to molecular properties of complex mixtures. However, the traditional concept of acoustic microsensors gaining (bio)chemical sensitivity from specifically interacting molecules or chemically sensitive thin films deposited onto the resonator surface can be exploited as well.