The First Ever Projector Smartwatch?

Similar to a hologram, a smartwatch developed by researched at Carnegie Mellon University and ASU Tech projects an interactive surface area on the wearer's arm or hand. This means that you can tap or swipe on your skin to use the watch. The watch is made up of a logic board, projector, depth sensor, metal enclosure, and battery. The projection is bright enough to be seen outdoors and can be used for 1 hour of continuous projection. However, with intermittent use, it is anticipated to last an entire day.

Although this smartwatch is not the first to project images on the wearer's skin, it is the first to project a useable on-body interface. However, this function causes the smartwatch to be bulkier than average. But with further research, the abilities of the smartwatch would be improved, and the size may also be reduced.

https://www.theverge.com/circuitbreaker/2018/4/27/17289572/lumiwatch-projector-smartwatch-arm-touch-screen