It's drones versus droids, in an online-shopping showdown. Hot on the heels of the weekend's revelation that Amazon is developing a line of autonomous flying delivery drones, Google has revealed that it is developing humanoid robots that could one day carry groceries to your door. Andy Rubin, the Google executive who brought smartphones to the masses by developing Google's free Android software, has revealed he is working on a project for the search engine company to create the new generation of robots. Rubin resigned unexpectedly from running Android in March, and has since quietly overseen Google's acquisition of seven small companies whose combined technology could be used to create a robot with animal-like characteristics such as a form of vision and moving limbs. "With robotics it's a green field," Rubin told The New York Times . "We're building hardware, we're building software, we're building systems, so one team will be able to understand the whole stack." Google robotics will be based in Palo Alto, California, and in Japan. The companies acquired include Industrial Perception, an American start-up that has developed digital eyes and robot arms for use in loading trucks; Holomni, which produces caster wheels that can swivel in any direction; and Japan's Schaft, whose robots generate as much power as a human and have mastered stable biped walking to cope with uneven ground (they can even retain their balance against the force of a human kick). Sources say plans are to develop machines that can be used for a range of activities, from manufacturing small electronics like smartphones - still mostly assembled by hand - to packing goods in warehouses and ultimately making home deliveries. The recently launched Google shopping service, a pilot project, is already delivering goods in San Francisco from Walgreens pharmacies, Target discount stores and American Eagle Outfitters. Noel Sharkey, emeritus professor of artificial intelligence at the University of Sheffield, said: "This is a very exciting development at Google. The robotics community is waiting with bated breath to find out what is being planned. Clearly, given the companies that have been acquired this is going to be research on the development of humanoid robots. "People should not be worried that [the robots] will be super intelligent. It is more likely they are going to develop these for domestic purposes such as assistance in elder care or perhaps for bar work or as receptionists. We can only speculate. But with the kind of money that Google can throw into a project like this, it is likely to be astonishing."