Shown in the picture AVPageView 06042016 140756.bmpis an interdigital cantilever AFM tip, that uses laser interference between the stationary and movable fingers of the micromachined structure to determine the position of the tip in a sensitive manner.

This work was done while I was at my sabbatical in Stanford University, with the PhD student Scott Manalis, now a professor at Biomedical Engineering Department of MIT.