This Star Trek t-shirt includes a small electrolumniscent panel that creates the animated effect. A battery pack is hidden within the lining of the shirt according to the product description. The shirt can be purchased here
from Gadgets.co.uk for about $46.
This Star Trek T-Shirt has a thin electro luminescence panel that creates a super-bright and lightweight sci-fi beacon. A tiny battery pack is cleverly hidden in the lining of the shirt for maximum comfort, this can be easily removed to allow the t-shirt to be washed should you need to clean any Klingons from the starboard bow, or anywhere else for that matter.
The Star Trek Enterprise T-shirt is powered by 4 x AAA batteries. Thankfully unlike the Dilithium crystals used in Warp Drives, these can be purchased from our site along with the t-shirt, so you needn't ever worry about not having the power to be flashier than your fellow Trekkies.
Oh Gizmo says
these types of shirts are fairly common these days and they point out a couple others including a pong shirt