https://www.theverge.com/2018/7/13/17570538/apple-macbook-pro-keyboard-design-patent-dust-dirt-liquid-resistant-ifixit

Apple’s new MacBook Pro keyboards are slightly quieter than the ones found in the previous iteration of the laptop. But the company’s silence on the mechanism’s widespread mechanical issues, which Apple first acknowledged with a repair program last month, has left many scratching their heads and wondering if the new laptop’s largely unchanged keyboard is susceptible to dust and crumb contamination under the hood.

Now, iFixit says it’s uncovered something that indicates that the new MacBook Pro keyboards use a silicone membrane underneath each individual key to keep dirt and other unsavory particles from finding their way under the keyboard and locking it up. The repair organization dismantled a new 15-inch MacBook Pro keyboard to discover the new mechanism.