https://www.theverge.com/2018/3/9/17100594/apple-patent-dirt-debris-liquid-snacks

Apple filed a patent made public yesterday for a keyboard that resists crumbs. The patent describes two different ways that a keyboard can keep dirt out, either by sealing gaps off or having a membrane beneath each key that would blow out air every time a key is pressed, pushing out unwanted debris.

From the figures shown in the patent, it’s clear that Apple is considering many different approaches and alternatives to create a crumb-resistant keyboard. The patent was filed on September 8th, 2016, just a day after the company officially announced the iPhone 7 and iPhone 7 Plus.