EETimes reports that Rumbus presented the world's smallest camera at Trillion Sensors Summit being held in Stanford University these days. So far Medigus and Awaiba made the smallest sensors for endoscopy. Medigus' 1mm2 imager is said to cost about $1,000.
Rambus presented a lens-free camera that is said to be significantly cheaper and smaller than these tiniest imagers. The company created an 80um diffractive grating from which it was able to reconstruct a poor but visible image of the Mona Lisa. The technique requires significant computation to deliver even a blurry image, however the company sees an initial opportunity to enter the market as a thermal camera. The Mona Lisa picture required computation on the order of 350 million multiple-accumulates.
Rambus got its first experimental results back in August and it aims to publish the results soon.
Update: The presentation slides can be downloaded here.