The first self-powered video camera in the entire world is currently under development. According to released information, not only does the camera run without batteries, it has the ability to produce an image every second.
Researchers led by a scientist of Indian origin had to start by developing a prototype camera. For this, a pixel capable of measuring incident light and then converting that light into electric power was developed. As stated by Shree K. Nayar, study leader and TC Change Professor of Computer Science at Columbia University, this development is at the heart of a digital imaging revolution.
Nayar noted that in 2014 alone, some two billion cameras of varying kinds were sold throughout the world. With digital imaging, a number of emerging fields will be enabled. Among these are sensor networks, wearable devices, personalized medicine, smart environments, and the “Internet of Things”, among others.
As explained by Nayar, having the ability to capture high quality images with no external power supply would be extremely beneficial to the user. While Nayar acknowledges differences between solar panels and digital cameras exist, one converting light to power and the other measuring light, virtually the same components are used to construct both.
The primary component of the digital camera is an image sensor, which is comprised of literally millions of pixels. A photodiode is what enables the pixel to work, which when exposed to light produces an electric current. With this, every pixel can measure the intensity of light that falls on it.
In order to fabricate an image sensor that consisted for 30×40 pixels, Nayar along with his study colleagues worked with components off-the-shelf. As part of the prototype camera was a 3D printed body. In addition, each of the pixel’s photodiode always used the photovoltaic mode to operate.
While the pixel design might seem complex, in reality it is rather simple. Using only two transistors, pixels first record and then read out the image during each capture cycle. From there, energy is harvested and the sensor’s power supply charged as the image sensor continuously toggles between modes of image capture and power harvesting.
One of the extraordinary features of the camera is that when it is not being used to capture images, power for other devices like a watch or phone can be generated. Nayar also points out that the image sensor of the camera can use a rechargeable battery and charge using its capability of harvesting.
On a final note, Nayar stated that energy can be harvested from several different designs for image sensors already proposed. However, what makes his prototype camera so unique is that it is truly the world’s first 100% self-powered video camera.