Hood lift mechanisms for reversibly increasing the energy absorption
capability at appropriate force levels of a vehicle closure includes a
vehicle closure; an active material in operative communication with the
vehicle closure, wherein the active material comprises a shape memory
alloy, a ferromagnetic shape memory alloy, a shape memory polymer, a
magnetorheological fluid, an electroactive polymer, a magnetorheological
elastomer, an electrorheological fluid, a piezoelectric material, an
ionic polymer metal composite, or combinations comprising at least one of
the foregoing active materials; and 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 increased clearance distance
between the vehicle closure and an underlying component.