Cantilever bending with rough surfaces

We show that the response of the curvature of cantilevers to changes in their surface stress depends significantly on the topology of the surface. The origin is the transverse coupling between the out-of-plane and in-plane components of the surface-induced stress. Deliberate structuring of the surface allows the magnitude and even sign of the cantilever response to be tuned, and experiments measuring the surface stress on nominally planar surfaces require a correction when there is roughness.