Solar purse sheds light on bag's innards

Ever stood outside on a freezing cold night rifling through a big ol' overstuffed purse for a pen, a cell phone, a spare quarter, a life-saving safety pin?

Rosanna Kilfedder, a 24-year-old design student at London's Brunel University, has. As is the case with true inventors, she didn't just fret about it, she designed a solution: the Sun Trap handbag, which has an electroluminescent interior light that goes on automatically when you unzip the bag.

Credit: Rosanna Kilfedder

"I had the idea for the Sun Trap handbag after seeing so many friends frantically searching their bags for house keys, usually on a dark doorstep," Kilfedder said. "I also noticed friends using their mobile phones like torches to examine the contents of their bag, which gave me the idea of lighting up the bag."

The purse uses a solar cell to trap energy from sunlight, storing it in the bag's internal battery. The lining goes dark automatically as the zip is closed or switches off after 15 seconds to conserve battery if the bag is accidentally left open. The internal battery also acts as a portable renewable energy source and can be used to charge mobile phones, PDAs and other wireless devices while on the move.

Brunel Enterprise Centre, which helps students and academics develop their ideas commercially, is helping Kilfedder apply for patents to cover the Sun Trap's zip and handbag. Kildeffer--who won a design competition at Brunel this summer--says a selection of original Sun Trap evening bags will be for sale on her Web site in the near future.

Brunel design students are an industrious lot. Their past inventions include a that records the number of daily steps taken, then transmits the tally to a base station using a radio signal; and that display lap count and time on the inside of the lenses.