Silicon valley's bet on the device that comes after the smartphone

Inside a former horse stable in the San Francisco neighborhood of SoMa, a wave of gentle chirps emerged from small, blinking devices pinned to the chests of employees at a startup called Humane. It was just weeks before the Ai Pin would be revealed to the world -- a culmination of five years, $240 million in funding, 25 patents, a steady drumbeat of hype and partnerships with top tech companies, including OpenAI, Microsoft and Salesforce.