Italian car designer Leonardo Fioravanti (of Pininfarina fame) has developed a prototype car with a windshield that doesn't need wipers. It can brush away water and dirt all by itself.I do wonder if objects hitting the windshield would cause the treatments to deteriorate over time though. As it is right now, a windshield can take a lot of abuse, and small debris, particles, and bugs hit it constantly.
The car, dubbed Hidra, uses a special aerodynamic design along with four sophisticated surface treatments to the windshield to keep the driver's view clear. The first treatment filters the sun and repels water. The second is made of nano-dust which is able to push dirt to the edges of the glass. This dust is activated by the third layer, which senses dirt and activates the second layer as necessary. Finally, it's all topped off by the fourth layer which is a conductor of electricity to power the whole mechanism.
Fioravanti claims that this technology could go into mass production within 5 years, but it already works and has been installed on the Hidra concept car.