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Home / News / Your next Apple Watch might read your sweat to tell you to drink more water

Your next Apple Watch might read your sweat to tell you to drink more water

There's a patent for a new perspiration sensor for the Apple Watch, that would detect your hydration levels from your sweat.

Apple Watch Series 9

While the latest Apple Watch only hit the shelves a few months ago, the rumour mill is churning out plenty of chatter about the next model. And the latest new feature comes from a patent Apple recently filed. This time, it’s all about getting sweaty – or rather, measuring it precisely. The tech giant might be adding perspiration sensors to the Apple Watch that can measure your sweat to work out how hydrated (or not) you are.

Back in August 2021, Patently Apple threw us a tech bone with an IP report hinting at the future of Apple Watches being hydration gurus. The idea is simple yet genius: to track your hydration levels. Because, let’s face it, who remembers to drink water when we’re too busy doomscrolling? Fast-forward to today, and Patently Apple has found a new patent from Apple introducing a new perspiration sensor system.

This Apple Watch wizardry uses a bunch of electrodes to detect how much sweat you’re producing. During a perspiration measurement session (which sounds awfully official), it connects a set of these electrodes to some capacitive measurement circuitry, and performs capacitance measurements. Then, voilà – you get your perspiration metric. Essentially, it uses a small measurement to detect how much sweat you’ve got going on.

A diagram of the new Apple Watch sensors
This new sensor would be crammed into the back of your Apple Watch to keep an eye on your sweat.

It also doubles as an ECG machine. Because why not throw in a bit of heart monitoring into the mix? This dual functionality kicks in when you’re sweating it out during your exercise session. Your Apple Watch could be programmed to start measuring your sweat rate automatically, giving you metrics like fluid loss per hour or total fluid loss over a specific period. It’s handy for those who like to know exactly how much they’re sweating it out on a 5k run.

But this estimated sweat rate isn’t just for kicks. It’s used to calculate other fun metrics like your hydration level, workout intensity, and even calories burned. It would add some extra fitness features to the most popular smartwatch. Of course, this sweat measuring sensor may never see the light of day. But it’s interesting to see Apple exploring ways to beef up your watch’s fitness tracking.

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Connor is a writer for Stuff, working across the magazine and the Stuff.tv website. He has been writing for around seven years now, with writing across the web and in print too. Connor has experience on most major platforms, though does hold a place in his heart for macOS, iOS/iPadOS, electric vehicles, and smartphone tech. Just like everyone else around here, he’s a fan of gadgets of all sorts! Aside from writing, Connor is involved in the startup scene. This exciting involvement puts him at the front of new and exciting tech, always on the lookout for innovating products.

Areas of expertise

Mobile, macOS, EVs, smart home

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