The Skin Buttons project by Carnegie Mellon's Future Interfaces Group is taking digital projections to a new level. Working buttons are projected onto skin. This is done by using small lasers to create small, bright red icons from the bottom of a wrist watch. The touch-sensitive buttons can be designed in any shape as well and therefore display a variety of information.
Described as "cheap, small, low-power and clickable fixed-icon laser projections," Skin Buttons were developed by Xiang 'Anthony' Chen, Chris Harrison, Scott E. Hudson, Gierad Laput and Robert Xiao of the university's Human-Computer Interaction Institute.
As John Biggs of TechCrunch explains, "by expanding a watch interface off of the physical object you get a bigger palette on which to create." This also allows users to interact with the interface without making the screen larger.
The Digitally Projected Skin Buttons Expand the Watch's Interface
Alyson Wyers — October 30, 2014 — Tech
References: figlab & techcrunch