A releasable fastener system comprises a loop portion and a hook portion. The
loop
portion includes a support and a loop material disposed on one side thereof. The
hook portion generally includes a support and a plurality of closely spaced upstanding
hook elements extending from one side thereof, wherein the plurality of hook elements
comprises a first portion fabricated from a shape memory material and at least
one additional portion fabricated from a different shape memory material. An activation
device is coupled to the plurality of hook elements, the activation device being
operable to selectively provide an activation signal to the plurality of hook elements
to change a shape orientation, a yield strength property, a flexural modulus property,
or a combination thereof to reduce a shear force and/or a pull-off force of an
engaged hook and loop portion. When the hook portion and loop portion are pressed
together they interlock to form a releasable engagement. The resulting joint created
by the engagement is relatively resistant to shear and pull forces and weak in
peel strength forces. Introducing a suitable activation signal to the plurality
of hook elements causes a change in shape orientation, flexural modulus property,
or a combination thereof that is effectively reduces the shear and/or pull off
forces in the releasable engagement. In this manner, disengagement of the releasable
fastener system provides separation of the hook portion from the loop portion under
controlled conditions. Also disclosed herein are processes for operating the releasable
fastener system.