Rollerball: a semi-autonomous colon robot

This miniature robot prototype was developed for inspection of the human colon, as an alternative to conventional colonoscopy. The novel locomotion mechanism, which uses three spherical wheels at the end of expanding arms, allows the robot to move through roughly cylindrical environments with a wide (approximately 3 fold) variability in diameter. The wheels are independently actuated, allowing the robot to change direction and overcome relatively sharp corners. Although it was designed for the colon (a flexible biological “pipe”), the compact physical platform and agile locomotion mechanism would make it well suited to pipe inspection tasks in other contexts.