At the Mobile World Congress 2015 in Barcelona this month, Japanese device maker Kyocera displayed a prototype of its smartphone that incorporates solar power technology into the touchscreen that allows the device to be charged both outdoors and indoors. The innovation marks a new approach to solving battery life problems through the environment around the smartphone.

Some phones, such as Samsung's Blue Earth, come with solar cells embedded on the back, which, however, is obscured by the hand while the phone is being used, resulting in only the screen receiving the maximum exposure to light. Kyocera's transparent solar technology developed in partnership with SunPartner Technologies has been incorporated into the screen of the Japanese device maker's Torque smartphone prototype built for rugged outdoor use.

The solar layer, which is incorporated below the touch layer in the phone screen, houses transparent crystals that absorb light and a chip to convert the energy and feed it into the phone battery. Less than 0.5 millimeters thick, the solar layer is thin enough to be incorporated into existing phones and its transparency of up to 90 percent does not interfere with the quality of the images.

Currently, the solar layer can generate 100 minutes of standby use and about two minutes of talk time to a smartphone's battery after 10 minutes of exposure to sunlight. In its present form, the technology is unlikely to replace the plug-and-charge smartphone battery, though users will be able to use it to access apps and information on their phones for a brief period after the battery becomes completely dead. The technology could come in especially handy during emergency situations, though its use may be limited during the day time.

Kyocera's Torque smartphone prototype is unlikely to make it to the market, though SunPartner is working on the technology for smartphone and tablet cases and covers, which could soon come to the market.