| Abstract: | Microelectromechanical (MEM) buckling beam thermal actuators are
disclosed wherein the buckling direction of a beam is constrained to a
desired direction of actuation, which can be in-plane or out-of-plane
with respect to a support substrate. The actuators comprise
as-fabricated, linear beams of uniform cross section supported above the
substrate by supports which rigidly attach a beam to the substrate. The
beams can be heated by methods including the passage of an electrical
current through them. The buckling direction of an initially straight
beam upon heating and expansion is controlled by incorporating one or
more directional constraints attached to the substrate and proximal to
the mid-point of the beam. In the event that the beam initially buckles
in an undesired direction, deformation of the beam induced by contact
with a directional constraint generates an opposing force to re-direct
the buckling beam into the desired direction. The displacement and force
generated by the movement of the buckling beam can be harnessed to
perform useful work, such as closing contacts in an electrical switch. |