By harvesting light for power, this tiny camera could be hidden anywhere and never run out of power.
A new, millimetre-wide, light-powered camera could herald a new wave of ultra-small and almost unnoticeable imaging devices. It's self-powered and microscopic in size meaning this new camera could be placed absolutely anywhere and run for decades without ever needing to be disturbed – it's a snooper's dream, basically.
Implications of voyeurism and security concerns aside, this tiny camera technology is undoubtedly one of the coolest advances in imaging since the dawn of affordable high-resolution imaging sensors. Its size is only made possible thanks to a team of University of Michigan engineers proving camera sensors can actually be powered by the light that hits them to create an image.
The breakthrough technological research comes from utilising both functions of a photovoltaic cell at the same time. Like a normal imaging sensor, it creates a picture by recording how much light energy hits its cells. Unlike any other imaging sensor, however, it also stores that energy to help power the process of image generation.
This may sound simple enough, in principle, but in reality, it's impossible to have a single sensor that can perform both operations simultaneously – it's got to either be harvesting energy or recording light. Instead of simply splitting the sensor in half, using part of it to record light and the other to utilise it for energy, researchers solved this problem by stacking sensors.
Euisik Yoon and his post-doctorate partner Sung-Yun Park discovered that the individual diodes on a photovoltaic cell aren't completely opaque. By stacking a solar cell directly behind that of an imaging sensor, it's possible to capture both an image and power a device at the same time. This breakthrough led to the creation of this microscopic imaging sensor that's less than a single square millimetre and powered by sunlight.
As you'd expect from a first-wave invention of this sort, the images it produces aren't exactly pin-sharp. However, they are still impressively detailed and Park informed IEEE Spectrum that better images could be produced with a few simple tweaks to the sensor, especially as power consumption is yet to be optimised.
Now, before you go reaching for your tinfoil-hat or believing you're soon going to be watched from every inch of the world, this is simply the creation of an imaging sensor. Cameras are more than simply an imaging component, requiring a means for storage and data transfer to really be deemed a functional camera. While we're not far off microscopic versions of those components, there's still a fair few years to go before the Illuminati can begin creating them, let alone install one in your kitchen.