Concrete can look uniform at a glance. Zoom in to explore the grains and pores visible through a downward-facing microscope. These surface details provide distinctive features that a robot can match to a map to determine its position.

About the images. The wider views are stitched together from microscope images. The dashed box outlines a single image (9.57 × 7.17 mm; each image pixel covers 2.36 µm of the surface). This demo zooms digitally; all images were captured at the same optical magnification.