Future Apple Watch will know how sweaty you are, if this new patent bears fruit

Apple Watch Series 9 Review
(Image credit: Future)

The Apple Watch is filled with a whole host of different sensors to make tracking your health and fitness easier, and this patent hints at another that could come to future generations.

Back in 2021, a patent revealed Apple’s plans to add a hydration measurement to the Apple Watch, which could “measure levels of electrolytes in perspiration.” Adding hydration measurement would be an incredible health feature on Apple Watch, allowing users to know how dehydrated or hydrated they are during exercise.

Now, nearly three years later, the U.S. Patent and Trademark Office has published a new patent application from Apple detailing a whole new hydration sensor system.

Initially reported by PatentlyApple, the patent covers “systems, devices, and methods for calculating a perspiration metric of a user.”

The patent reads, “In some embodiments, a device may include a perspiration sensor having first and second electrodes positioned on a skin-facing exterior surface of the device. Capacitance circuitry may measure a capacitance between the electrodes, which may be used to calculate the perspiration metric. In some embodiments, the device defines a cavity such that one or both of the electrodes extend at least partially into the cavity.

Other embodiments include a second perspiration sensor, and measurements from the second perspiration sensor may be used in calculating the perspiration metric.”

More sensors for the Apple Watch

In other words, the Apple Watch could activate when it detects sweat and track your hydration levels during exercise. The Apple Watch is already the number one health and fitness wearable in the world, but if we were to see hydration sensors implemented, it would take the Watch to a whole new level.

The Apple Watch has been in the media a lot recently concerning the blood oxygen sensor that has now been banned for the time being in the U.S. following Apple’s legal battle with health technology company, Masimo. That said, the best Apple Watches are still fantastic products, and we hope to see blood oxygen return to the U.S. sooner rather than later.

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John-Anthony Disotto
How To Editor

John-Anthony Disotto is the How To Editor of iMore, ensuring you can get the most from your Apple products and helping fix things when your technology isn’t behaving itself.

Living in Scotland, where he worked for Apple as a technician focused on iOS and iPhone repairs at the Genius Bar, John-Anthony has used the Apple ecosystem for over a decade and prides himself in his ability to complete his Apple Watch activity rings.

John-Anthony has previously worked in editorial for collectable TCG websites and graduated from The University of Strathclyde where he won the Scottish Student Journalism Award for Website of the Year as Editor-in-Chief of his university paper. He is also an avid film geek, having previously written film reviews and received the Edinburgh International Film Festival Student Critics award in 2019. 

John-Anthony also loves to tinker with other non-Apple technology and enjoys playing around with game emulation and Linux on his Steam Deck.

In his spare time, John-Anthony can be found watching any sport under the sun from football to darts, taking the term “Lego house” far too literally as he runs out of space to display any more plastic bricks, or chilling on the couch with his French Bulldog, Kermit.