Can zombies use touchscreens?

With Halloween just around the corner, and the fifth season of The Walking Dead in full swing, we've been thinking a lot about zombies.

Specifically, we wanted to know: Can a zombie use a touchscreen? Could a zombie, for instance, pick up an iPad and actually play Plants vs. Zombies?

"It depends on how recently the person has passed into the beyond," says Ken Hinckley, a Principal Researcher at Microsoft Research whose work focuses on touch-sensing input devices.

It's all about moisture

Hinckley says the zombie's moisture content is key. "If there's a bit of water left in the corpse it would still respond. But if [the zombie] was desiccated and dried out, it might not respond anymore."

That's because most smartphones and tablets use capacitive touchscreens, which rely on the conductive properties of our fingers.

"Humans are essentially giant bags of water," Hinckley says. "And so, the capacitance sensors in the touchscreen are picking that up. So as long as you have something that can conduct electricity and it's wet, that should work. I think zombies should qualify, so long as they haven't dried out."

What about ghosts?

So, if a zombie gets holds of your device, it might be able to rack up credit card charges for in-app purchases.

But what about ghosts?

"A ghost is non-corporeal," Hinckley asserts. "In terms of sensing contact, you need to have some sort of corporeal form."

So then, when the zombie apocalypse comes, it's best to keep your tablet and smartphones away from the walking dead.