Vader could take food through his mouth, but only when he was inside a hyperbaric chamber, since he had to remove his triangular respiratory vent. ... Though liquids were preferable, he still had the capacity to chew if he wished, though a nutrient feed provided Vader with all the nourishment he required.

Does Darth Vader sleep?

When Vader did sleep, he was awoken soon after by a disturbing series of visions, sounds and pain, most of which including Obi-Wan or Padme. It's entirely possible that he never really needed to sleep given the powers of his mechanical suit, however, his brain was still completely biological.

How does Vader shower?

The Darth Vader shower head is a removable bath head that is shaped like the face of Darth Vader, and when you turn him on water shoots out of his eyes like laser beams in hopes to scrub the geekiness levels off of you. Though, there's 3 different spray settings where water also comes out of his mouth or forehead.