[zem]

i'm guessing (backed up by the photo) that his proof-of-concept is literally a generator in the shoe hooked up to an attached bulb, so that when he walks a bit the bulb lights up.

[dbbolton]

What about the "cum" in the middle of the sentence?

[baddox]

It's Latin for "with." It's usually used with hyphens to describe something with dual purpose, so it would be more appropriate to spell it "shoe-cum-charger." It's also used in purely Latin phrases like magna cum laude.

[dbbolton]

I knew the Latin meaning. I've honestly never seen it used as a direct replacement for "with" in an otherwise all-English phrase though.

[zem]

extremely common in india, particularly in the phrase sofa-cum-bed.