There arethat aim to make your walk in the rain a little more bearable. Some let you or on the underside of your brollie. Korean designer Sang-Kyun Park's LightDrops creation lights your way in the rain.
According to the writeup on Yanko Design, the outside canopy has a conductive membrane called PDVF. As rain comes down, the impact generates electrical energy that powers built-in LEDs on the umbrella. The harder the rain hits, the brighter the light. Now that's literally a brilliant idea, but the lights better be waterproof or you'll end up as an electrifying light show.
(Via Crave Asia)