Abstract
Piezoelectricity and shape-memory are the two smart properties which have been widely and separately used in many fields. In this research, a new kind of nano composite is prepared to combine these two smart properties in one kind of material. Most composites of piezoelectric materials and shape-memory materials are made by bonding multiple layers in different materials, however, the interface between layers usually become the weak point because of the poor combination of different kinds of materials. In view of this problem, the new composite is made of lead zirconate titanate (PZT) nano particles and shape-memory polyurethane (PU). It is a great challenge to disperse high weight density particles (PZT) homogeneously in low weight density solvent (PU dissolved in tetrahydrofuran) without chemically surface modification on particles. Another challenge is how to keep the two smart properties well after compounding the new composite. This new composite is produced by mixing PZT particles and PU in tetrahydrofuran, casting and hot-press. The Field Emission Scanning Electron Microscope (FE-SEM) images of this new composite containing 60% (weight percent) PZT show the well dispersion of the PZT nano particles in PU. The experiment results show that this new composite has very strong shape-memory property and piezoelectricity. Taking advantages of two smart properties in one material, this new composite has the promising potential to be developed into self-sensing material. With the advantage of PZT particles, this new composite can be utilized as actuators and sensors in nanofabrication. It also can be made into devices in different shapes to be applied in different conditions according to PU's flexibility.
