Scientists Develop Artificial Retina From Perovskite Materials

Apr, 2022 - By WMR

The new artificial retina built out of perovskite materials detects light in a similar way as the human eye and can recognize handwritten numbers

In an attempt to build better options for computer vision application, a group of researchers developed an artificial retina from perovskite materials that can detect light and recognize handwritten numbers in way similar to that of the human eye, as the researchers tried to imitate the process of human or other mammals’ eye, in which photoreceptor cells in the retina absorb incoming photons and pass electric signals to the brain.

In this new research, the team used a material called perovskite, which is known absorb light with high efficiency and it is becoming popular in the solar cells industry. In the research, the team derived the light-absorbing ability of this material to create a sensor. The team embedded nanocrystals of perovskite into a polymer and then put this layer in between two electrode, indium tin oxide on the top and aluminum on the bottom. The upper electrode was fixed to allow the light enter and reach perovskite layer. This created an array of photoreceptors, which are created on a polymide substrate that enables the device bend and flex into any required shape such as shape of a human retina.

Furthermore, for the light input to process, the team attached the photoreceptor array to a CMOS sensor and a neural network having 100 output neurons. When tested with a 4x4 array, the device lit with the help of LEDs of different colors, where the team found that the optical response was same as that of the human eye and the system was specifically sensitive to green light. Moreover, the device could also recognize handwritten numbers with 72% accuracy. However, the new artificial retina is not expected to be used for human transplant. Nonetheless, with more development, it could be used for developing more advanced vision systems for robots and cameras.