The image recognition systems contain several electronic circuits necessary for their operation : an image sensor, a storage device and another information processing . The challenge to successfully manufacture artificial retinas is to bring these functions into devices small enough to fit into a human eye . The solution is to build a single structure with a size of a nanometer , such as a nano- switch .

A nano – switch consists of two electrodes separated by a tiny space , one being metallic and the other consists of a solid electrolyte . For an electrochemical reaction in solid phase , metal atoms extracted from the electrolyte to form a bridge between the two electrodes and thus close the switch . When the space between two electrodes is in the nanometer range , the reaction is automatic which is not without problems in the quest for miniaturization of these devices. Researchers have therefore introduced between the two electrodes a membrane whose electrical conductivity varies with the intensity of light received . In the presence of light, the membrane becomes conductive , allowing a current flow between two electrodes, sufficient for the bridge can be formed and put the switch in the closed position . The researchers made sure the bridge remained in place even after the extinction of light which would allow the device to provide a memory function . They also verified that it was possible to control the destruction of the bridge and open the switch. Their statement does not , however information on the mechanism involved

The switch operates with voltages of several millivolts. By using several intermediate membrane switches have running lights of different wavelengths , it becomes possible to manufacture a system that recognizes colors. The researchers will now be focusing on a manufacturing system arranged on a flexible membrane so as to create an artificial retina.

Source:

NIMS News – 07/13/2010 (Japanese ) – http://www.nims.go.jp/news/press/2010/07/p201007130.html