From Google's Advanced Technology And Projects (ATAP), the Project Soli team is developing a new gesture interaction sensor using radar technology. The sensor can track sub-millimeter motions at high speed and accuracy. It fits onto a chip, can be produced at scale, and built into small devices and everyday objects. The interaction sensor runs at 60GHz and can capture motions of a user’s fingers at resolutions and speeds that haven’t been possible before - up to 10,000 frames per second. To get there, the team had to reinterpret traditional radar, which bounces a signal from an object and provides a single return ping. The team built the first prototype, which is a 5x5mm piece of silicon.