SHENZHEN Atall Intelligent Robot Technology has become one of China’s leading companies for robots equipped with artificial intelligence. But it’s best-selling product has one main function.

Meet Emma - the sex robot with artificial intelligence.

This multi-functional machine has soft and elastic skin made of modified thermoplastic elastomer material, less oil content and no smell. And its temperature is set to 37C to resemble a human's.

It is also linked to the internet, features an Android operating system and has high stimulation capabilities.

Camera Icon An AI sex doll robot with a screen in a head on display at the Shenzhen Atall Intelligent Robot Technology show room in Guangzhou, Guandong Province, China. Credit: Aleksandar Plavevski

For those concerned about safety issues, the robots are fitted with anti-electric shock, anti-fire and anti-explosion measures. And the addition of body sensors help make sex robots feel more like a person.

But this semblance of authenticity doesn't come cheap with Emma’s online retail price about 20,000 RMB ($A4,136). Most customers are men aged between 40 and 50.

The company has an investment deal with the Chinese government to produce and supply AI robots for education and presentations, and for taking care of elderly people.

But it is the sex robots that have boomed.

While there is strong demand locally, most other clients are from Europe and the US.

And each nationality has a preference.

Camera Icon A worker puts the final touches on to onto the face of one of the robots. Credit: Aleksandar Plavevski

According to the company, French customers tend to like robots with blond curly hair, blue eyes, tanned skin, and hairless genitals with natural pink colour. Spanish customers prefer robots with darker skin and hair, full lips and larger, pink genitals. About 70 per cent of this market prefers pubic hair on the machines.

Customers from the US are pickier and often request changes to the genitals' colour and hair but prefer darker skin, and large breasts and buttocks and genitals. The Chinese go for dolls with Asian features, and small, pink, hairless genitals.

Male sex robots are also available but sales are nine times lower compared to female models.

Shenzhen Atall CEO Wang Shao Fang said because China was becoming an ageing society it believed the demand for these AI robots would increase.

But despite the impressive functionality of the Emma, the company’s chief engineer believes it will take 10 to 20 more years of development until the robots were fully functional - being able to move like humans - or be available at an affordable price.