It sounds just a little creepy, I know. Nonetheless, right here’s what Apple says:
“In some examples, detecting the quantity of drive applied to an interface floor may also be completed with a drive decay sensor disposed within the interior extent. This power decay sensor can also be surprisingly small and affordable and might be disposed of at nearly any desired place within the inner volume. This makes it possible for smaller contraptions or gadgets that encompass multiplied room for further or better components, as in comparison to a tool that contains an array of force detecting add-ons.
The drive decay sensor can notice an increase within the force of the internal volume that may also be attributed to the deflection or deformation of the interface floor when a drive is utilized thereto, and can extra realize the cost of decay of the force. The quantity of force can also be as a minimum in part in response to the detected expense of decay.”