SELFIE SCIENCE
It’s hard to imagine that mobile phones ever existed without a camera. That was until American physicist Eric Fossum created the pixel image sensor, paving the way for modern-day smartphone cameras and webcams. It was created in NASA’s Jet Propulsion Laboratory back in 1993. The intention was to invent cameras small enough for interplanetary space travel. However, Fossum’s ‘camera-on-a-chip’ technology quickly proved valuable for many different industries, including the invention of the camera phone. The camera in your smartphone evolved from Fossum’s original complementary metal-oxidesemiconductor (CMOS) active pixel image sensor. The sensor works using an array of pixel sensors covered by colour filters and a photodiode – a device that converts light into an electrical current. As light passes over the surface of the sensor, it is detected and converted into an electrical signal before it is amplified by several transistors. These signals are then interpreted as an image.