Bi-stable fastening

A touch fastener comprising a hook component and a loop component, each of the hook and loop components having exposed elements on an active side thereof for releasable engagement with the exposed elements of the other component;

• the active side of one of the hook and loop components comprising a surface that bi-stabilizes between a first stable form for initiating engagement with the active side of the other of the hook and loop components, and a stable, concave form for securing an initiated engagement of the other of the hook and loop components, wherein
• the exposed elements of the hook component comprise hooks, and
• the heads of at least two adjacent hooks contact one another when the bi-stabilizing surface is in its stable, concave form, to secure engaged loop component elements.

A touch fastener comprising a pair of releasably engageable components, each of the components having exposed elements on an active side thereof for releasable engagement with the exposed elements of the other component;

• the active side of one of the components comprising a surface that bi-stabilizes between a first stable form for initiating engagement with the active side of the other of the components, and a stable, concave form for securing an initiated engagement of the other of the components, wherein
• the exposed elements of one of the components comprise mushroom-shaped hooks each having a head wherein the heads of at least two adjacent hooks contact one another when the bi-stabilizing surface is in its stable, concave form, and wherein
• the exposed elements of the other component comprise fibers exposed for engagement by the hooks to secure engagement between the pair of component elements.