Electrically Controlled Piezoelectric Motion of Piezoelectric Chiral Polymeric Fibers

The electrically controlled piezoelectric motion of a fiber of poly(L-lactic acid) (PLLA), a type of chiral polymer, is invertigated. Laser light was propagted into the PLLA fiber and when the controlling electric field was applied to the fiber, the direction of the outgoing beam from the fiber changed owing to its piezoelectric motion. The change in direction was recorded using two charge coupled device (CCD) video cameras: one faces the tip of the PLLA fiber and the other is placed above the tip of the fiber. First it was realized that the outgoing beam moved in a zigzag manner when we applied the ac voltage with high harmonic waves to the PLLA fiber. Furthermore, when a component parallel to the PLLA fiber axis of the applied electric field was generated, the trajectory of the outgoing beam changed from a straight line to an ellipse.