Imagine the day when you can grab your phone, snap a great photo or video, and never again get that annoying alert that there will be no picture or video taking until the battery has more juice.

Engineers believe they may have invented a video camera that doesn't need a battery charge, acccording to new research from Columbia University's School of Engineering and Applied Science.

Researchers report they have built a video camera prototype that is literally "self powering," or in simple terms, there is no charging needed.

Lead researchers Shree K. Nayar and T.C. Chang, professor of computer science at Columbia Engineering, say the first ever self-powered camera delivers an image each second as long as the smartphone camera is focused on what constitutes an "indoor" photo environment

"We are in the middle of a digital imaging revolution," said Nayar. "I think we have just seen the tip of the iceberg. Digital imaging is expected to enable many emerging fields including wearable devices, sensor networks, smart environments, personalized medicine, and the Internet of Things. A camera that can function as an untethered device forever—without any external power supply—would be incredibly useful."

Yes, that is true, but a battery charge lasting more than 12 hours on a smartphone would be incredibly useful as well, as most smartphone users would attest.

The research team, led by Nayar in collaboration with Daniel Sims, a research engineer, and Mikahair Fridberg of ADSP Consulting, tapped existing technology to develop [pdf] an image sensor boasting 30 x 40 pixels.

The team's prototype camera, encompassed in a 3D printed body, directs each pixel's photodiode into a photovoltaic mode.

"We took an extreme approach to demonstrate that the sensor is indeed truly self-powered and used just a capacitor to store the harvested energy," said Nayar. "A few different designs for image sensors that can harvest energy have been proposed in the past. However, our prototype is the first demonstration of a fully self-powered video camera."

That, he believes, may also foster a new generation of camera technology.

"We believe our results are a significant step forward in developing an entirely new generation of cameras that can function for a very long duration—ideally, forever—without being externally powered," stated Nayar.