A patent application from Nokia describes a cell phone that charges itself with kinetic energy.
The "Piezoelectric Kinetic Energy Harvester" works a lot like those kinetic energy watches that charge when the wearer moves his or her hand. The phone's battery is held in a frame, and is attached to a second frame containing piezoelectric elements. When the user twists or moves the phone, those elements create an electric field, and a power controller harvests the energy. Nokia says other elements of the phone, such as the keyboard or display, could also be used as mass to feed the piezoelectric elements.
Nokia doesn't expect that this technology will completely recharge a cell phone, but notes that as smartphones and mobile devices become more powerful, with better features and services, they consume more energy, and battery life is a problem. "Kinetic energy harvesting has the potential to at least partially address this challenge," the patent application says.
This idea makes a lot more sense than solar cell phone chargers, which some manufacturers are including or plan to include in their phones. My phone spends the most time in my pocket or indoors. It's pretty rare for me to leave my phone in direct sunlight, especially for the amount of time needed for a solar charger to work.
With kinetic energy, just walking around with the phone in your pocket could be enough to give a cell phone a boost, and same goes for having a conversation or playing a mobile game that uses accelerometer controls.
Nokia could be years away from actually building a phone with this technology, but I have a feeling smartphone battery life will be a major battleground by then -- as it is now with laptops -- so this is a smart patent to file.
