| 摘要 |
An optical based authentication device that is attachable to a security document having a substrate. The authentication device includes: a piezoelectric material layer for generating an electric field in response to mechanical stress; and an optically responsive layer directly attached to the piezoelectric material layer, the attached layers being absent a direct electrical connection, the optically responsive layer being operable between a first state and a second state having different ocular perceptions. The optically responsive layer changes from the first state to the second state in response the electric field generated by the piezoelectric material layer. |
