Bifunctional molecules and methods for their use are provided. The additive may be prepared starting with crystalline, fused or amorphous silica powder, thereby reducing the cost of the additive as compared to using precipitated silica. These elements may be arranged to propagate mechanical motion generated by the converter sub-unit through the coupler and optionally into the edge of the attached material. The vertical arch member and the lateral support supportably position the rigid canopy in a predetermined horizontal orientation.