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Recent advances provide new opportunities in the field of polymer piezoelectric materials. Piezoelectric materials provide unique insights to the fundamental understanding of the solid state. In addition, piezoelectric materials have a wide range of applications, representing billions of dollars of commercial applications. However, inorganic piezoelectric materials have limitations that polymer ferroelectric materials can overcome, if certain challenges can be addressed. This mini-review is a practical summary of the current research and future directions in the investigation and application of piezoelectric materials with an emphasis on polymeric piezoelectric materials. We will assume that the reader is well versed in the subject of polymers, but not as familiar with piezoelectric materials.

A shear-bending mode high temperature piezoelectric actuator Experimental results of the nonlinear dynamic response of a piezoelectric high displacement actuator known as thin-layer composite unimorph ferroelectric driver and sensor were compared to a theoretical model, which utilizes the multiple scales method to connect the effective spring constant to higher-order stiffness constants c 4 of the piezoelectric layer. This type of actuator has prestress gradients resulting from the manufacturing process that have been reported to play an important role in enhanced actuation. A value of c 4 = −4.7ϫ 10 20 N/m 2 was obtained for the higher-order lead zirconate titanate ͑PZT͒ stiffness coefficient, which is higher than other published results for PZT without prestress gradients. Peak resonance displacements over 1 mm were obtained for even small ͑100 V pp ͒ applied fields. The analysis showed a slight voltage dependence that was not specifically accounted for in the theory. This was confirmed by recasting data from other published results and further confirmed by dc offset studies reported here.

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Morphing wing technologies provide expanded functionality in piloted and robotic aircra, extending particular vehicle mission parameters as well as increasing the role of aviation in both military and civilian applications. However, realizing control surfaces that do not void the bene�ts of morphing wings presents challenges that can be addressed with micro�ber composite actuators (MFCs). We present two approaches for realizing control surfaces. In one approach, �ap-like structures are formed by bonding MFCs to each side of a metal substrate. In the other approach, MFCs are bonded directly to the wing. Counter intuitively, the �ap approach resulted in larger voltage actuation curvatures, with increased mass load. Actuation performance, de�ned as the ratio of curvature per applied voltage, was as large as 5.8 ± 0.2 × 10 −4 (kV⋅mm) −1 . e direct bonding approach reveals that at zero wing pressure, up to 63 ± 3 m of displacement could be realized.