Google's taking its Ara modular smartphone platform increasingly seriously, and in this video it lays bare some of the challenges it's been facing—and how it's overcoming them.

The overall concept of Ara is to produce a modular smartphone—with a basic version costing just $50—that users can tweak and upgrade themselves. It's a neat idea, but one which requires plenty of engineering insight. This video shows off an early iteration of Ara's endoskeleton , a silver frame into which extra modules are slotted. What's neat is that they're locked in place using electro-permanent magnets, which means that an app can be used to lock them in place so they never budge. The upshot: the phone won't need an external case. Elsewhere, Google engineers talk about the early designs for the casing of Ara's modules—which should be customizable, with textured effects and bright colors.

The overall feel of the video is one of open honesty: this is a tough project, and not all the goals are easily achievable, but Google's willing to admit that's the case. It also makes us want to try out the result more than ever. [Phonebloks via Engadget]