DNA nanobot
Micro-bots
http://techland.time.com/2012/02/29/five-miniature-robots-designed-to-travel-inside-of-humans/?iid=tl-main-feature#micro-bots
Wirelessly powered medical device
http://techland.time.com/2012/02/29/five-miniature-robots-designed-to-travel-inside-of-humans/?iid=tl-main-feature#wirelessly-powered-medical-device
DNA nanorobot
http://techland.time.com/2012/02/29/five-miniature-robots-designed-to-travel-inside-of-humans/?iid=tl-main-feature#magmite
Spider robot
http://techland.time.com/2012/02/29/five-miniature-robots-designed-to-travel-inside-of-humans/?iid=tl-main-feature#spider-robot