An acceleration sensor includes a semiconductor substrate, a first layer formed on the substrate, a first aperture within the first layer, and a beam coupled at a first end to the substrate and suspended above the first layer for a portion of the length thereof. The beam includes a first boss coupled to a lower surface thereof and suspended within the first aperture, and a second boss coupled to an upper surface of the second end of the beam. A second layer is positioned on the first layer over the beam and includes a second aperture within which the second boss is suspended by the beam. Contact surfaces are positioned within the apertures such that acceleration of the substrate exceeding a selected threshold in either direction along a selected axis will cause the beam to flex counter to the direction of acceleration and make contact through one of the bosses with one of the contact surfaces.