First picked up by AppleInsider, the U.S. Patent and Trademark Office published details on Apple's designs for "Modular functional band links for wearable devices", which first surfaced last April.
The patent describes a band made of a series of modular links containing electronic components, which are attached to each other using a flexible conductive material.
A number of possible uses are mentioned for the linked design, including batteries, speakers, kinetic power generators, haptic feedback devices, and more. Biometric sensors are also covered, such as blood pressure monitors and sweat sensors.
The modular accessory links are arranged serially across a power circuit and communications bus, with module control achieved by way of a unique identifier assigned to each link. In one example, an audio signal is sent from the timepiece through the chain of linked modules and activates only those modules assigned with a particular identifier.
Other examples describe links being used as external ports for interfacing with off-device components such as expandable memory modules. In most of the embodiments, the modular links connect to a 6-pin diagnostic port on the watch.
As always, there's no suggestion that the invention should be expected to appear in a finished product, but the patent does highlight Apple's continuing search for ways to expand the capabilities of a future Apple Watch or other wearable beyond the chassis, which could ultimately extend the life cycle of the watch body and allow future updates to come in the form of new band accessories.