Spray-On Plastic Image Sensors Developed
From cellphones and tablets, to computers and game consoles, cameras surround us. A key reason these devices have become as prolific as they have is because of the compact, silicon-based sensor system they use. Now researchers at the Technische Universitaet Muenchen have found a plastic replacement to the silicon sensor that also performs better in multiple ways.
Within a digital camera is an image sensor made of silicon, using a CMOS process. When light falls on the sensor it is converted into an electrical signal and transmitted to an image processor via electronics attached to each pixel, which can block some of the light. What the researchers have found is an organic compound that can be sprayed onto the electronics as an ultra-thin film, to replace the traditional silicon pixels. As it is sprayed on, the material can cover all of the electronics, making the entire surface light sensitive. The material is also as much as three times more sensitive to light than silicon, which allows some post-processing steps to be skipped when producing the sensor.
Of course at this point a camera has to be able to take color images, and there are multiple ways of doing that. For the plastic sensor, different polymers can be used, as they will respond to different parts of the spectrum, from the visible region to the infrared. This could open up new imaging possibilities which are traditionally too expensive to explore.