It wasn’t long ago that I was thinking about how a purpose-built gaming smartwatch could incorporate a controller without being a bulky and annoying POS. Depending on how responsive this is, we might have an answer with this prototype watch that was designed by students at Carnegie Mellon University. The virtual buttons are projected on to the wrist of the wearer and infrared proximity sensors are used to determine whether or not they are being pushed.
This was developed after Gierad Laput, a PhD student, asked “how do you make a watch bigger without actually making it bigger?” The reason he asked such a question was that the rather small screens of smartwatches certainly limit the ways in which users can interact with them. Part of the problem is that the user obscures most of the screen when inputting data, and part of the problem is just a lack of freedom for UI designers. This solution widens designer freedoms and moves the input to the sides of the watch; very clever.