US Patent 7331616 Hood latch assemblies utilizing active materials and methods of use

A latch for engaging and disengaging two opposing surfaces includes a pin disposed on one surface and a gate disposed on an opposite surface; an active material in operative communication with the pin or the gate; an activation device in operative communication with the active material, wherein the activation device is operable to selectively apply an activation signal to the active material and effect a reversible change in a property of the active material, wherein the reversible change results in an engagement or a disengagement of the pin or the gate from the other of the pin or the gate; and a spring in operative communication with the pin or the gate, wherein the spring is configured to provide a force opposite to a force provided by the active material, wherein the activated active material is effective to overcome the force provided by the spring