Smartwatch

Overview

A smartwatch is a wrist-worn computer that combines a touchscreen, health sensors, and wireless radios in a sealed case small enough to wear continuously. This cellular model can place calls and stream data independently of a phone. The engineering problem is density: a full sensor suite, radios, and a battery must fit under a 45 mm case while staying water-resistant to 50 metres.

The structural shell is the Case Assembly, an aluminium body capped with a scratch-resistant sapphire crystal that protects the Display Module, an always-on OLED touchscreen tuned for outdoor visibility. Behind the display sits the Mainboard (SiP), a system-in-package that fuses the processor, memory, and radios into one compact module.

Construction

Health tracking is the core function, performed by the Sensor Array on the underside of the case. It shines light into the skin to read heart rate and blood oxygen optically, takes an ECG across electrodes, and tracks motion with an accelerometer and gyroscope. GPS provides location for workouts and navigation.

Power is held in the Battery Pack, a small lithium-polymer cell managed for both runtime and long-term cycle life. It recharges without contacts through the Wireless Charging Coil, a Qi receiver that picks up energy inductively from a charging puck. Connectivity runs through the Antenna Set, which packs cellular, Wi-Fi, Bluetooth, and GPS antennas into the case perimeter.

Interaction blends touch with the Digital Crown, a rotary input for precise scrolling without covering the screen. Feedback comes through the Taptic Engine, a haptic motor for taps and alerts, and the Audio Module speaker and microphone for calls. Water resistance is held by the Water-Seal Gasket Kit gaskets, and the watch attaches to the wrist through interchangeable Strap bands on quick-release lugs.