Let's take a gander under the hood of the Taptic Engine, shall we?

The rubber we hoped to simply cut open needed to be cut away chunk by chunk.

Finally, the coils are free! Well, bare at least.

Force Touch looks to be a clever application of a technology that dates back a ways—the year 1824, to be exact.

Made of wire coils surrounding a ferromagnetic core, the electromagnet in the Force Touch Trackpad is used to create the vibrational feedback you feel.

We're guessing that the four separate coils here are used to vary the feedback given to the user. Turning different sets of the four coils on and off varies the strength and direction of the vibration, and how it feels to your finger.