Soli is a new sensing technology that uses miniature radar to detect touchless gesture interactions. 

Soli is a purpose-built interaction sensor that uses radar for motion tracking of the human hand. The sensor tracks sub-millimeter motion at high speeds with great accuracy. 

They are creating a ubiquitous gesture interaction language that will allow people to control devices with a simple, universal set of gestures.

Google envisions a future in which the human hand becomes a universal input device for interacting with technology. 

How it works

Soli sensor technology works by emitting electromagnetic waves in a broad beam.

Objects within the beam scatter this energy, reflecting some portion back towards the radar antenna. Properties of the reflected signal, such as energy, time delay, and frequency shift capture rich information about the object’s characteristics and dynamics, including size, shape, orientation, material, distance, and velocity.

Soli tracks and recognizes dynamic gestures expressed by fine motions of the fingers and hand. In order to accomplish this with a single chip sensor, they developed a novel radar sensing paradigm with tailored hardware, software, and algorithms. Unlike traditional radar sensors, Soli does not require large bandwidth and high spatial resolution; in fact, Soli’s spatial resolution is coarser than the scale of most fine finger gestures. Instead, their fundamental sensing principles rely on motion resolution by extracting subtle changes in the received signal over time. By processing these temporal signal variations, Soli can distinguish complex finger movements and deforming hand shapes within its field.

Source: Google