Piezoelectric MEMS devices
MEMS components based on the piezoelectric effect have many advantages over capacitive or thermal conversion principles. However, since the effect is typically very small, a major challenge lies in developing components that can still interact sufficiently with their environment.
Advanced piezo and flexoelectric materials
Piezoelectric thin films enable the direct conversion of electrical and mechanical energy and can therefore be used both as sensor layers and as actuator layers. The integration of material systems such as aluminum nitride (AlN) or polyvinylidene fluoride (PVDF) and polyvinylidene fluoride-co-trifluoroethylene (PVDF-TrFE) into existing MEMS technology processes requires an in-depth understanding of the relationship between manufacturing and material properties.
A non-linear electro-mechanical coupling that occurs especially with thin layers <100 nm is the flexoelectric effect. In this effect, inhomogeneous strain of the material induces polarization. The flexo-electric can even outweigh the piezoelectric effect in thin layers, making it a highly exciting topic for future ultrathin MEMS and NEMS.