Wearable Health Tech devices have all sorts of sensors, and many include cameras. These can be used for the prosaic tasks of capturing still images or video, but that’s just the start. Giving a device the power of vision means that it can detect gestures that could be used to control a user interface. It could use it for face recognition, helping the wearer navigate around obstacles, and a host of other useful tasks. But these sensors require power. Or do they?
Researchers at Columbia University’s Computer Vision Laboratory have created a self-powered camera. The principle is based on a pretty simple concept. The way digital cameras work is that the light sensors for each pixel in the image measure the amount of light at that spot. That measurement takes the form of a small electrical current that can be detected by the controller and converted into pixel data. The new idea is that when the camera is not being used to capture an image, those electrical currents can be stored in a battery for later use, or in this case, a supercapacitor. This approach is different from putting dedicated photovoltaic devices among the pixel sensors.
The demonstration camera is large and clunky with a low monochrome resolution of just 30 by 40 pixels, but the concept is sound. The device can store enough power in a second to capture an image. The principle could be adapted to small, integrated camera chips, which could harvest some or all of the energy required by a wearable Health Tech device.