Sex robots have soft and elastic skin made of modified thermoplastic elastomer material, with less oil content and no smell. Its temperature is set to 37C to resemble a human's.
Safety issues are managed 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 a semblance of authenticity doesn't come cheap, and Emma's online retail price is about 20,000 RMB ($A4,136) with most customers being men aged 40-50.
The company already has an investment deal with the Chinese government for producing and supplying AI robots for education and presentations, and others for taking care of elderly people.
Most other clients are from Europe and the US.
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 on the market but the sales volume is nine times lower compared to the female models.
The fact that China is becoming an aging society means that the market size for these robots will be huge, says Shenzhen Atall CEO Wang Shao Fang.
Despite the impressive functionality, it will take 10-20 more years of development until fully functional robots - that can move their hands and walk like humans - will be available on the market at an affordable price, his chief engineer says.