With China facing a massive gender gap and a greying population, a company wants to hook up lonely men and retirees with a new kind of companion: "Smart" sex dolls that can talk, play music and turn on dishwashers.

Rows of voluptuous silicon bodies hang in the warehouse of EXDOLL, a firm based in the northeastern port city of Dalian, but engineers are also working on bringing them to life.

A programmer in a lab coat asks a petite blonde prototype sitting on a chair and dressed in a see-through white blouse: "What is your name?"

"My name is Xiaodie but you can also call me baby. But if I'm not happy I won't answer," the robotic voice says through a speaker, though its lips do not move.

EXDOLL has ambitions to apply artificial intelligence to make dolls so life-like that they could cure loneliness among the country's singletons and care for the elderly and handicapped.

There are 33.6 million more men than women in the country of 1.4 billion people.

EXDOLL has ambitions to apply artificial intelligence to make dolls so life-like they could cure loneliness among China's singletons and care for the elderly and handicapped FRED DUFOUR, AFP

The gap is attributed to China's former one-child policy and a traditional preference for sons, which has led to selective and illegal abortion. Some 114 boys are born for every 100 girls, far above the global average.

China also has a rapidly ageing population, which is putting strains on the healthcare and social welfare system.

Seated between two non-robotic silicon companions, one in a short black skirt and a smaller model in a schoolgirl outfit, marketing director Wu Xingliang said his company's products could solve the country's major social problems.

"China has a shortage of women, and this is a factor in why there's this demand, but they're not just for sex," Wu, whose customers include single young and older men but also married ones, told AFP.

"We're designing them so they can have meaningful conversations with you and help with chores around the house. They could eventually even work as medical assistants or receptionists," Wu said.

- 'Hottest body' -

Xiaodie is essentially a sex doll fitted with a wifi function similar to the iPhone's Siri application, which can surf the internet and respond to voice commands.

Buyers can customise each doll for height, skin tone, breast size, amount of pubic hair, eye colour and hair colour FRED DUFOUR, AFP

It can turn home appliances that are connected to the wifi on and off.

Users can control the 25,000 yuan ($4,000) doll with a phone app or by giving it oral instructions -- much pricier than the traditional sex dolls that the company sells for as little as 2,500 yuan.

In the next year, EXDOLL hopes to roll out more advanced robots featuring artificial intelligence technology, complex facial expressions and body movements, voice recognition systems and eyes that can follow people's movements.

A shapely prototype in a racy white dress bows to greet male engineers at the factory.

The programmers pore over 3-D models on computer screens while another one assembles a skeleton with exposed wires and joints -- reminiscent of the white droids in the Will Smith sci-fi film "I, Robot".

China is estimated to make more than 80 percent of the world's sex toys, with over a million people employed in the country's $6.6 billion industry FRED DUFOUR, AFP

The machine becomes more lifelike as he gingerly affixes a silicon skin -- handpainted in sultry makeup colours -- over its face.

Qiao Wu, chief development officer at EXDOLL, said the goal is to create the most beautiful and most human-like robot possible.

"There are already good robot technologies developed, so we want to concentrate on having a robot with the most beautiful face, and the hottest body," he said.

- 'Friends of dolls' -

The company makes 400 custom dolls per month, up from 10 in 2009. It began research into sexbots in mid-2016 and now employs 120 people.

On the factory floor for "traditional" sex dolls, Wu points out that buyers can customise each doll for height, skin tone, breast size, amount of pubic hair, eye colour and hair colour.

The company makes 400 custom dolls per month, up from 10 in 2009 FRED DUFOUR, AFP

However, the most popular dolls have pale skin, disproportionately swelled breasts and measure between 158 and 170 centimetres (five foot two and five foot seven) tall.

When asked whether smaller models are supposed to resemble children, Wu recoiled and said they were diminutive because some customers prefer "less heavy" and "more portable" dolls.

On Chinese social media, some say the products reinforce sexist stereotypes or endorse paedophilia.

"When sex robots become more technologically advanced, will men prefer to use them instead of respecting human wives?" one commenter on the Twitter-like Weibo platform wrote.

Others, calling themselves "friends of dolls", share user reviews and advice on dedicated online forums.

"The material is quite good, very soft to the touch. When I hold her I feel very comfortable," one anonymous user said in a review of a standard sex doll on e-commerce platform Taobao.

On Chinese social media, some say the dolls reinforce sexist stereotypes while others, calling themselves 'friends of dolls', share user reviews on dedicated online forums FRED DUFOUR, AFP

China is estimated to make more than 80 percent of the world's sex toys, with over a million people employed in the country's $6.6 billion industry.

Prominent Chinese feminist Xiao Meili thinks that some men will always have outdated expectations and "sex housewife robots" might actually help women.

"A lot of men want the same for women: sex, housework, childbirth and filial piety. They don't think of women as individuals," Xiao told AFP.

"If every nerd buys a sex doll for himself ... that would free a lot of women from these kind of men."