Apple appears to be preparing a more advanced smartwatch as successor to the recently launched and released Apple Watch 2. The upcoming wearable is said to come with heart rate sensors embedded into the wristband instead of the device’s body. 

In an Apple patent obtained by Apple Insider on Thursday, it was found out that the Cupertino giant is looking into placing the heart rate sensor at the end of the strap that would come with the device. To ensure that the sensor is protected from wear and tear due to wrist movement, Apple is also considering active fluid technology for its new smartwatch. 

The patent mentions a versatile technology that’s composed of transparent structures and electrically active fluid, which is capable of responding to applied voltage. In addition, the fluid being considered for the wristband is also suggested to contain crystalline structures that would alter their state and color when exposed to applied voltage. 

According to Apple Insider, the patent includes descriptions for a transparent smartwatch strap that would contain the color-changing fluid. The transparent material would be advantageous in this case because it would complement the conductive ink when it switches colors every time the user touches the wristband or when voltage is applied. This is seen as a visual notification system, since each color could indicate a certain type of notification.

The possible new location of the heart rate sensor is seen as a big improvement in terms of collecting wrist data. In fact, engineers of Apple’s first smartwatch actually suggested prior the creation of the first-generation device to have the heart rate sensor placed in the strap. However, Apple opted to place the sensor in the body of the timepice, since it was releasing interchangeable straps for the Apple Watch.

There are other embodiments included in the patent that was originally filed in June 2015 and was published by the U.S. Patent and Trademark Office. But all of them highlight how active fluid would provide different functionalities to the next Apple Watch. 

Apple is known to patent a lot of ideas. Just recently, it was found out that the tech giant event filed for a patent for its rectangular shopping bags that are made from bleached sulfate paper. The Chicago Tribune has learned that the patent points out things that make Apple’s shopping bags for its retail stores far superior than others. 

The patent — filed last week — indicated that Apple uses at least 60 percent of recycled material for its bags  that have a “sophisticated fit and finish” unlike the shopping bags of its rivals that only use up to 40 to 50 percent of recycled material and typically have “rough and dull fit and finish.”