Preparation of Piezoelectric Paints and Application as Vibration Modal Sensors

Piezoelectric paints were prepared using lead zir conate titanate (PZT) ceramic powder as a pigment, and epoxy resin as a binder. The obtained paints were coated on aluminum beams and were dried at room temperature, thus forming films with thicknesses of 35 to 81 μm and PZT volume fractions of 30 to 53% . The films were then poled under electric fields of up to 350 kV/cm at room temperature, and the resulting piezoelectric activity was evaluated from vibration measurements on the aluminum beams. The piezoelectric activity obtained under a given poling field increases with increasing film thickness and with increasing volume fraction of PZT. The piezoelectric activity of the PZT/epoxy paint film has proved to be high enough to determine the natural frequencies and mode shapes of a structural material, thus demonstrating the potential of the paint film as a built-in vibration modal sensor.