By combining a clever physical interface with computer-vision algorithms, researchers in MIT’s Department of Brain and Cognitive Sciences have created GelSight, a simple portable 3D imaging system that can achieve resolutions previously possible only with large and expensive lab equipment. The device could provide manufacturers with a way to inspect products too large to fit under a microscope and could also have applications in medicine, forensics and biometrics. GelSight is developed by MIT researchers, Edward Adelson and Micah Kimo Johnson.

GelSight Super-High-Resolution 3D Imaging

GelSight images particles of ink spelling the word 'ink' on a piece of paper

The heart of the system, dubbed GelSight, is a slab of transparent, synthetic rubber, one of whose sides is coated with a paint containing tiny flecks of metal. When pressed against the surface of an object, the paint-coated side of the slab deforms. Cameras mounted on the other side of the slab photograph the results, and computer-vision algorithms analyze the images.

Moreover, because GelSight makes multiple measurements of the rubber’s deformation, with light coming in at several different angles, it can produce 3D models of an object, which can be manipulated on a computer screen.

Traditionally, generating micrometer-scale images has required a large, expensive piece of equipment such as a confocal microscope or a white-light interferometer, which might take minutes or even hours to produce a 3-D image. Often, such a device has to be mounted on a vibration isolation table, which might consist of a granite slab held steady by shock absorbers. But Adelson and Johnson have built a prototype sensor, about the size of a soda can, which an operator can move over the surface of an object with one hand, and which produces 3D images almost instantly.