Project Ara had once been hotly anticipated as the future of mobile devices with enhanced future-proofing and general upgradeability. The prototype produced through this Google initiative was a basic frame to which various interchangeable modules could be attached. The project's public profile had dwindled since; however, it seems its makers haven't forgotten about it yet.
https://www.notebookcheck.net/Could-Project-Ara-possibly-be-back-Google-has-secured-a-new-patent-for-a-familiar-looking-modular-device.396296.0.html