In
Batman Begins the Caped Crusader's cape is made of memory fiber, a fictional product of Wayne Enterprises' Applied Science Division. This fiber becomes rigid via an electrical current and allows Batman to glide much like a base-jumper. Four physic students have written a paper entitled 'Trajectory of a falling Batman' which studies the realism of the cape. Through their research they believe that gliding would be possible, but Batman would travel at dangerously high speeds. As he would land it'd be like being hit by a car traveling at 50 miles per hour.
David Marshall, Tom Hands, Ian Griffiths and Gareth Douglas found that the wingspan of Batman's cape - at 4.7 metres - is around half that used by a hang glider. If Batman jumped from a building 150 metres high, he could glide a distance of around 350 metres - but the problem arises as Batman's velocity increases during his descent. His velocity would initially rise to around 68 miles per hour, before reaching a steady 50 miles per hour as he gets down to ground level - a speed too fast for him to land safely.
The students believe the best way to counter the hard landing would be to use parachutes, or jet propulsion.
You can read the full paper here:
physics.le.ac.uk/journals/index.php/pst/article/view/484/289
The Dark Knight Rises is now playing at your local theater. The film stars Christian Bale as Bruce Wayne/Batman, Michael Caine as Alfred Pennyworth, Gary Oldman as Jim Gordon, Tom Hardy as Bane, Anne Hathaway as Selina Kyle, Joseph Gordon-Levitt as John Blake and Marion Cotillard as Miranda Tate.