If you use your phone a lot during the day, then keeping it charged can be a challenge. Sure, you can always plug it in to a charger as you go from place to place, but all of that plugging and unplugging can be a pain. To make life easier, a group of researchers developed a new type of material that constantly tops up the charge as your phone gets moved and jostled while you drive.
Dr. Xudong Wang at the University of Wisconsin in Madison, working in collaboration with researchers at Sun Yat-sen University in China, developed a material that is able to turn small levels of vibrational energy into electricity. Dr. Wang says that their mesoporous piezoelectric nanogenerator, uses the piezoelectric properties of polyvinylidene fluoride to generate enough power to trickle charge small electronic devices such as smartphones. While this type of energy can be generated whenever the phone is moved, it's most effective in the presence of a steady source of vibration such as in a moving car.
Of course, a cheap car is probably going to have more vibration than some huge luxury model, so I guess those rich Bentley owners might not get too much of a charge. So for once, it's the little guy who gets a break. I expect I'll be in pretty good shape with my rattly old Diesel.
The nanogenerator itself comes in the form of a thin flexible sandwich of materials, including a spongy layer of mesopores that are very effective at absorbing vibration. Dr. Wang says that this energy harvesting layer can be built into the structure of the phone itself, or attached externally. You could, for example, build a phone case that's lined with the material along a built-in connector to charge the phone, or you could design something like an in-car phone mount that does the same thing.
Dr. Wang didn't give a time frame for when the vibration charger might be turned into a commercial product, but I do look forward to the day when we no longer have to be constantly on the lookout for outlets or carry portable battery packs.