Retailers are buying robots in record numbers, and you’ve probably seen them in stores. San Diego robotics company Brain Corp has deployed more than 50,000 robots around the world with its AI software and reported record growth of 68% in sales this year. Now these robots are working overtime in stores from Walmart and Sam’s Club to Target, taking inventory and scrubbing floors. Brain Corp has been around since 2009 and has raised more than $220 million building robots to automate jobs that are “dull, dangerous and dirty,” said John Black, chief technology officer at Brain Corp. Their most well-known robots look like small Zambonis, autonomously cleaning grocery store aisles.