Patent ID: 7798090

Claim:
A signaling device comprising: a detectable element having a border area, a center axis, a substantially planar upper surface and a substantially planar lower surface; and at least two directional biasing elements associated the border area of the lower surface, said directional biasing elements having a drag end and a directional end, wherein the drag end of one directional biasing element is separated from the drag end of the other directional biasing element by the center axis, and wherein the drag end of one directional biasing element is oriented in a substantially opposite direction than the drag end of the other directional biasing element, wherein the detectable element includes a substantially planar laminate comprising a first layer and a second layer, said first layer being substantially optically clear, and said second layer being associated with the directional biasing elements and having thermal energy absorptive properties; and wherein intermediate the first layer and the second layer is an electromagnetic generating element.