Apple's patent FIG. 4 below presents a clamshell style smartphone with multiple layers of functional components. One side is a keypad which could be a force touch based instead of mechanical, while the other side is for text, messages and other visual information.
Apple updated their patent in 2021 and on Tuesday (Jan 10th) Apple was granted this patent under # US 11550369 B2 titled "Multi-part Device Enclosure." You could review this patent and its 20 new patent claims here.
Keep in mind that this isn't a design patent and so the patent figures presented above from Apple are only based on providing an overview of the invention, not the actual design.
The Digital Crown for ECG
Apple has been granted a patent for the Apple Watch input feature known as the "Digital Crown." Apple's patent is titled "Switch Module For Electronic Crown Assembly." More specifically, this granted patent relates to the Digital Crown in context with it being used an input for electrocardiogram (ECG) signals.
Apple's Patent Abstract: "A switch module for an electronic device detects translational inputs and defines at least portion of a conductive path from an input surface of the electronic device to a processing unit of the electronic device. The switch module may be a component of a crown assembly for detecting rotational inputs, translational inputs, touch inputs and/or biological signals such as electrocardiogram (ECG) signals. The switch module may include a conductive dome and a friction guard that is positioned between the conductive dome and the actuation member of the crown assembly. The conductive dome and/or the friction guard may define at least a portion of the conductive path from the input surface to the processing unit."
Apple's patent FIG. 1 covers a functional block of the Digital Crown, with FIG. 2A simply illustrating that this input in this patent is specifically designed for Apple Watch (not AirPods Max).