The OnBeat headphones
A Scottish audio engineer has created a range of headphones called OnBeat, that can charge phones and tablets using solar power. The headphones have a solar cell across the headband to collect energy from the Sun.
The solar cell on the OnBeat headphones has a surface area of 55 cm3 with a charge capacity of approximately 0.55W. It is made from poly-crystalline silicone and stores energy from the Sun in rechargeable Lithium Ion batteries fitted to each ear cup. The phone doesn't charge through the headphone jack, it is connected to the headphones using a USB port.