Apple's Watch is designed to be both fashionable and functional.
Apple Wins Patent for Pressure-Sensitive Device Casings
The patent, discovered by AppleInsider, combines two different methods of detecting and measuring the amount of pressure applied: one physical, the other electrical. The capacitance test, which works in a similar way to touchscreens, would enable the device to tell human touch apart from accidental pressure applied while the device was carried in a pocket or bag.
Sensors disposed within the housing, in some embodiments directly beneath the surface, can detect when deflection occurs, which in turn denotes stress or pressure. In some embodiments, the sensors are connected to a printed circuit board that can in turn illuminate a light or other indicator when a minimum amount of readable stress is applied … A processor can take the measurements with their corresponding deflection rates, and translate them into device actions. For example, a threshold stress level is reached when a user presses down on a certain area of a device's housing. The processor determines that the capacitance change is outside the bounds of normal readings and can trigger a UI event or other device feature in response. The system can be customized to detect patterns and varied sensitivities to support a broad range of tasks.Apple patents a great many technologies it never uses, either as potential solutions that are later rejected or to protect against competitor use, although the metal casing of the iPhone 5 could make the system practical on any future iPhone models with a similar casing.