Researchers at Carnegie Melon University and Arizona State University (ASU) have developed a new wearable wristwatch that projects a touchscreen image on the wearer’s forearm. Known as the LumiWatch, it creates a functional touchscreen interface that’s up to 15 inches in size on the user’s arm. To put that number into perspective, a typical touchscreen smartwatch is just 3 inches in size. So, how does the LumiWatch work exactly?

Although it looks simple enough (see image to the left), the LumiWatch is powered by some pretty impressive hardware. It features more than a dozen individual laser projectors as well as finger-tracking sensors, a Qualcomm quad-core processor, 768MB of RAM, 4GB of internal flash memory, a rechargeable 740 mAh battery and a Wi-Fi/Bluetooth adapter. Best of all, the LumiWatch comes with Google’s Android operating system (OS) already installed.

Researchers say that with the LumiWatch’s existing design, it offers about one hour of continuous use. When used sparingly, however, it can last for up to a full day on a single charge. If performance optimizations are made, the battery life may be further expanded.

The LumiWatch works by projecting lasers of three colors — red, blue and green — on the wearer’s warm. When the user touches his or her arm, it creates a disturbance in the lasers, thus allowing the LumiWatch to determine the user’s point of contact. It doesn’t just identify contact, though; it also tracks the user’s finger as it moves across the touchscreen area. This means users can perform swipe motions on their arm to control the LumiWatch. And the LumiWatch already has Android built into it, so users can access their email, the internet and Android apps.

Although obstacles remain for practical adoption, we believe our work demonstrates the first functional projection smartwatch system and constitutes a significant advance in the state of the art,” wrote the project’s researchers.

Unfortunately, it’s unknown when or if the LumiWatch will be released. Developers have already made a prototype, but they haven’t announced any official date for a public launch. Researchers did say, however, that the final product will likely cost around $600. With the Apple Watch 3 costs $329 to $399, that makes the LumiWatch a bit more expensive. In any case, it’s an innovative device that could spur new ideas among touchscreen manufacturers.

You can learn more about the touchscreen-projecting wristwatch by visiting lead researcher Robert Xiao’s website here.