Apple Patent Hints at Temperature Sensor for Apple Watch Series 8

Apple was granted a new patent, titled “Temperature gradient sensing in portable electronic devices,” on Tuesday that hints at a new temperature sensor for the Apple Watch Series 8 and details how the company’s implementation could potentially work (via MyHealthyApple).

The Cupertino, California-based tech giant is expected to unveil three new Apple Watch models at its September event: the Series 8, a low-end SE refresh, and a new “Pro” model geared toward extreme sports.

Both the Apple Watch Series 8 and the new Apple Watch Pro have been tipped to gain body temperature sensors. This new patent lends further credence to these rumours.

The problem with most applications of temperature sensing on wearables is that they occupy too much space. Wearables are usually outfitted with multiple temperature sensors, taking up invaluable space within already congested devices.

According to the patent, Apple plans to use just one temperature sensor instead of several to remedy that. Apple’s implementation comprises one temperature sensor and a thin-film differential temperature probe. The differential probe will include a flexible substrate that will be thermally coupled to the temperature sensor at one end, and to one of the device’s surfaces on the other.

To preserve space inside the chassis, the thin-film differential temperature probe could even be routed around, or through, other components of the device.

Apple said in its patent filing:

Broadly, a wearable electronic device incorporating a temperature sensing system as described herein can detect absolute temperature of multiple discrete locations or volumes without requiring multiple temperature discrete temperature sensors. As a result, a wearable electronic device can recover and/or reallocate substantial internal volume otherwise conventionally allocated to multiple temperature sensors and can be manufactured at lower cost without sacrificing performance of sensors of subsystems of the wearable electronic device that are temperature dependent.

A flexible differential temperature probe could be placed anywhere inside the wearable for optimum performance. It could even be affixed right against the back of a smartwatch, which directly touches the wearer’s skin. The probe could obtain a highly accurate measurement of the user’s body temperature in this manner.

Apple’s patent goes beyond just the Apple Watch and covers implementations of thermal sensing in other devices as well.

The company presented examples of wireless headphones or earbuds using an onboard temperature sensor to detect the temperature of the wearer’s inner ear, and the Apple Pencil using a temperature measurement system to know when the user is holding it.

Apple was originally expected to add a temperature sensor and more to the upcoming second-generation AirPods Pro for fitness tracking. However, more recent reports have indicated that is no longer happening.