Smartwatches are a promising new platform,
but due to their small size, even basic actions like navigation are cumbersome. There’s a great need for approaches that expand
the interactive envelope around smartwatches, allowing input to escape the small physical
confines of the device. We propose using very small projectors that
render *fixed-image* icons onto the skin, significantly expanding the interactive region
without increasing device footprint. Further, these icons can be made touch sensitive,
allowing for interactive applications. For example, projected icons could alert you
to a missed call or text message. Tapping on the application icon launches the
app. In this clock example, we use generic projected
icons coupled with small, on-screen labels. This allows skin buttons to be used for many
functions. Finally, with a navigation-centric icon set,
we can control applications without touching the screen, allowing for further miniaturization.
Here a user can navigate quickly and comfortably through songs and playlists. Our experiments show that these projectors
can be accurate, made very small and inexpensive, and have
negligible impact on battery life — in many cases they can save battery power
by keeping the main display off. In the future, instead of using film,
skin buttons could be made dynamic by using small LCD matrices.
Here’s a prototype using a 3 by 5 pixel matrix, but these could be made at a much higher resolution
in the near future.