A massive Japanese conglomerate is scooping up Boston Dynamics, the robotics firm behind many of the videos you may have seen online of amazing yet somewhat creepy automatons.

On Friday SoftBank said it had struck a deal to acquire Boston Dynamics from Alphabet, the parent company of Google, which had bought the robotics company in 2013 but decided last year to put it up for sale. Terms of the deal were not disclosed.

"Boston Dynamics are the clear technology leaders in advanced dynamic robots," SoftBank chief executive Masayoshi Son said in a statement. "I am thrilled to welcome them to the SoftBank family and look forward to supporting them as they continue to advance the field of robotics."

Boston Dynamics is widely known for developing robots with potential military applications. The robots are built to withstand substantial abuse. Videos on the company's YouTube channel show its four-legged contraptions recovering after being shoved and kicked, while its bipedal robots have been hit with hockey sticks.

When Alphabet signalled that it was looking to shed the company last year, reports suggested that one major factor was the high cost of developing the robots, along with a hazy path to market. Since Google reorganised as Alphabet in 2015, the company has ramped up its focus on financial sustainability — particularly among its other bets, which include Google Fiber, X and Nest.

It appears that SoftBank may be more willing to accept Boston Dynamics' leisurely R&D timeline. And it makes some sense culturally, too: As its population ages, Japan has turned increasingly to robots to make up for workers who are leaving the labor pool. More than 26 per cent of Japan's population is over the age of 60, according to the World Bank. As a result, Japan has invested heavily in robots for elderly care, hospitality and other applications, leading to a boom in the technology. In 2014, Prime Minister Shinzo Abe predicted that Japan's robot market will be worth $US21 billion by 2020.

Alphabet didn't immediately respond to a request for comment on the sale.

The Washington Post