In November 2013, the Make A Wish Foundation made one little boy’s dream of being Batman’s sidekick and saving Gotham City from evil doers come true. The city was transformed into a real life Gotham with the villains that Batman and his new sidekick BatKid need to put away and save the girl.
Batman has usually always had the best in technology. It was always small enough to fit on his person and always had enough power to do anything he wanted. So for the BatKid, he needed a way to signal and call Batman, so what better way to do this than with a custom built Bat signal projector and communicator. With a tiny pico projector you can make Batman techonology.
We found an instructable that will allow you to call Batman whenever you need him.
See the instructable here:
http://www.instructables.com/id/Batkid-Tech-3-Wrist-Projector-Communicator/step1/Proof-of-concept/