It's a bright spring morning in Hanover, Germany, and I'm on my way to meet a robot.

I have been invited to see the G1, a humanoid robot built by Chinese firm, Unitree, at the Hannover Messe, one of the world's largest industrial trade shows.

Standing at about 4'3" (130cm), G1 is smaller and more affordable than other humanoid robots on the market, and has such a highly fluid range of motion and dexterity that videos of it performing dance numbers and martial arts have gone viral.

Today the G1 is being controlled remotely by Pedro Zheng, the Unitree sales manager.

He explains that customers must program each G1 for autonomous functions.

Passers-by stop and actively try to engage with the G1, which cannot be said for a lot of the other machines being shown off in the cavernous conference room.

They reach out to shake its hand, make sudden movements to see if it will respond, they laugh when G1 waves or bends backwards, they apologise if they bump into it. There's something about its human shape that, uncanny as it is, sets people at ease.

Unitree is just one of dozens of companies around the world developing robots that have a human form.

The potential is huge - for business it promises a workforce that doesn't need holidays or pay rises.

It could also be the ultimate domestic appliance. After all, who wouldn't want a machine that could do the laundry and stack the dishwasher.

But the technology is still some way off. While robotic arms and mobile robots have been common in factories and warehouses for decades, conditions in those workplaces can be controlled and workers can be kept safe.

Introducing a humanoid robot to a less predictable environment, like a restaurant or a home, is a much more difficult problem.

To be useful humanoid robots would have to be strong, but that also........

© BBC