Imagining the Apple Watch Series 4

<!––>Every year since the Apple Watch’s debut, a new hardware version has been released. The OG Watch dropped in 2015, the Series 1 and 2 hit in 2016, and the Series 3 was released this past fall. Should this pattern hold, the Apple Watch Series 4 will show up later this year.

What hardware improvements could we hope for in the Series 4? Here are the changes I would like to see:

Better heart rate sensor

The Apple Watch may well have the best wrist-based heart rate sensor in the industry. But it’s not good enough. On runs, my Watch often fails to register my pulse at all. Once it does, it’s comically incorrect—either 30 BPM too high or “half off,” as if it’s missing every other heartbeat. I’d almost rather not have a heartrate reading at all than one I can’t trust for adjusting my effort level.

Now, we may be running up against physics here. Like all other wrist-based heart trackers, the Watch uses an optical sensor; green LEDs illuminate the blood flowing through your wrist. Apparently, that’s not a particularly reliable way to measure heart rate.¹

But if it’s possible to either a) improve the optical heart rate tech or b) adopt some other, more reliable technology, I’d love to see Apple do it. Right now, I bring both the Apple Watch and my chest strap on runs. That’s annoying.

Always-on screen

It’s right there on the tin. The Apple “Watch” is a “watch”—i.e., a wrist-worn device for telling the time. But compared to every other “dumb” watch on the market, the Watch does worse at performing this basic task.

The Apple Watch manages its power aggressively, switching off the screen after a few seconds of inactivity. If you steal a glance at the device without raising your wrist—say, while you’re typing or reading or eating or driving—you’re greeted by a black, blank screen. If you do flip your wrist, the Watch often fails to register this movement and stays dark.

Given the Series 3’s stellar battery life, I’d like to see Apple loosen the power management reins a bit, in favor of an always-available clock. Just light up enough pixels to show the current time. The Series 4 could still hide its complications (weather, Activity rings, sports scores, etc.) until I raised my wrist; fade them in when you’re sure I’m watching. But at all other moments of the day, show the time in dimly-lit, grayish digits, glanceable from any angle.

Thinner body

The Watch has always seemed a bit chunky, and it’s actually been getting chunkier with each successive generation. It’s time to reverse that trend. My ideal Apple Watch would be about 25% thinner than the Series 3 and would feel less like a nerd-alert badge on my wrist. That may not be possible this year, but I’ll be irked if the Watch gets thicker again.

Slimmer bezels

Because the Apple Watch cleverly blends its bezels with its OLED screen, it’s easy to miss just how wide those bezels are. In the era of “edge-to-edge” phone displays, I’d like to see that tech trickle down to Apple’s wearable devices. Push those corners out just a bit with the next hardware revision.

Longshots: glucose monitor and temperature sensing

Finally, two less-likely hopes for an Apple Watch Series 4:

• Last year, Apple was rumored to be developing a blood sugar sensor that worked without piercing your skin. This would be a godsend for diabetics, but it could also help non-diabetics get a better handle on healthy eating. I’d be less likely to down a Coke if I could see exactly how high it spikes my glucose levels.
• Finally, temperature sensors could be fun. What if the Series 4 Watch could detect your body temperature and the ambient air temperature? There are algorithmic challenges here, of course; your wrist’s temperature may not reflect your core heat, and body heat would throw off ambient readings. But maybe Apple could correct for these problems. Imagine a Watch that could detect a fever before other symptoms arise. Or a Watch that could confirm, once and for all, that your favorite restaurant sets its thermostat three degrees too cold. ■