Robotic Finger Image
The Digger Finger robot digs through granular material, like sand and gravel, and senses the shapes of buried objects. (Image courtesy of the researchers

MIT researchers have designed a sharp-tipped robot finger equipped with tactile sensing to meet the challenge of identifying buried objects. Digger Finger was able to dig through granular media such as sand and rice and correctly sense the shapes of submerged items it encountered.

Seeking to identify objects buried in granular material — sand, gravel, and other types of loosely packed particles — isn’t a brand-new quest. Previously, researchers used technologies that sense the subterranean from above such as Ground Penetrating Radar or ultrasonic vibrations. But these techniques provide only a hazy view of submerged objects.

Operators will have to adjust the Digger Finger’s motion pattern for different settings, depending on the type of media and on the size and shape of the grains. The team plans to keep exploring new motions to optimize the Digger Finger’s ability to navigate various media.