A one-chip scanning retina with an integrated micromechanical scanning actuator

A microsensor that merges sensing and scanning functions on a single chip has been designed and fabricated, resulting in the first integrated scanning retina of its kind. A microfabrication technique has been developed to combine a one-dimensional array of photodiodes and electrostatically driven scanning slits on a single chip. The scanner actuates 12-mum-wide microslits by up to 20 mum on top of 30-mum-wide photodiodes, and the motion generates an effect similar to that of the retinal scanning vergence found in the insects' compound eyes. The silicon retina is coupled with an array of 120-mum-diameter microlenses to compose a microsized scanning compound eye, and the effect of retinal scanning in edge and position detection is demonstrated with the sensor. Each individual visual unit of the compound eye detects light contrast due to the scanning motion of the visual axis. The architecture of this scanning retina increases the resolution of a visual system with a relatively small number of receptors.