Soli is a radar emitter/detector system that sees and interprets hand and finger motions. It is a very small (smaller than a dime) and is designed to be included in smartphones, tablets, PCs, Internet of Things, etc. It is very precise due to its high sampling rate (at 10,000 frames per second) and processing power included on the chip.
During prototyping the device started out the size of a pizza box, and has since been drastically miniaturized to the point that it could be included in smartphones and other consumer products.
It should be available to developers later this year.
Here’s a video demo that shows how it works at a high level. https://youtu.be/0QNiZfSsPc0