GelSight: Retrographic Sensing for Touch, Texture and Shape

GelSight is a novel technology for measuring high-resolution surface topography. GelSight was introduced at CVPR 2009, and since that time we have pushed the boundaries of resolution and sensitivity. Our latest design is capable of measuring surface features as small as 2 microns spatially with submicron depth resolution. We have made two prototypes based on this design, a bench configuration and a handheld portable configuration.

GelSight is a novel device that can be used as a 2.5D “scanner” for acquiring surface texture and shape. It consists of a slab of clear elastomer covered with a reflective skin. When an object presses on the skin, the skin distorts to take on the shape of the object’s surface. When viewed from behind (through the elastomer slab), the skin appears as a relief replica of the surface. The surface geometry of the object can then be estimated using photometric stereo techniques. There is no problem dealing with transparent or specular materials because the skin supplies its own BRDF. Complete information is recorded in a single frame; therefore we can record video of the changing deformation of the skin, and then generate an animation of the changing surface. The GelSight sensor has no moving parts (other than the elastomer slab), uses inexpensive materials, and can be made into a portable device that can be used “in the field” to record surface shape and texture.