I’m taking a look inside the Oura ring, a fitness tracker that looks like a piece of jewelry. Oura’s tech focuses heavily on sleep tracking, which makes sense to me since it’s way more comfortable than any wristband I’ve tried. It’s so teeny, and waterproof, I’m super curious about what’s inside. I set out to take apart both a Gen 2 and a Gen 3 Oura ring, as well as one charging base. I anticipated having trouble getting to see the actual circuit board up close, so before cracking at them with cutting tools, I sent them off to be CT scanned at a company called Lumafield. Their Neptune machine makes it easy to see inside 3D objects and explore the different materials that make them up, in a smaller and easier to use form factor than traditional CT scanners.

Parts we could identify on the Gen 2 Oura ring

While it’s super cool that you can do a teardown without tearing anything down these days — thanks to the CT scan — most of the analysis is done on a cut-up version of the thing through a normal stereo microscope. Still, the ability to then flip over to a 3D CT scan of the thing is nice.

We absolutely concur with [Becky] and [David] that it’s astounding how much was fit into very little space. Somewhere along the way, [David] muses that the electrical, mechanical, and software design teams must have all worked tightly together on this project to pull it off, and it shows. All along, there’s a nice running dialog on how you know what you’re looking at when tearing at a new device, and it’s nice to look over their shoulders.

Then there’s the bit where [Becky] shows you what a lithium-ion battery pack looks like when you cut it in half. She says it was already mostly discharged, and she didn’t burst into flames. But take it easy out there! (Also, make sure you take your hot xylene out on the patio.)