The artist has battled surveillance, underground exile and even irate Berlin taxi drivers. He thinks the world has forgotten what human rights mean, which is why he has designed a new flag

The wallpaper image on Ai Weiwei’s mobile phone is a black and white photograph showing the entrance to an underground home in Xinjiang. It was here where the Chinese activist artist and his family were exiled for five years when he was a boy. “We were put underground here as a punishment,” he says. “This is where I grew up. Now they put the Uighurs in these kind of camps.” He enlarges the picture showing a bunker-like structure jutting out of the ground in an arid, inhospitable landscape.

Ai’s father, Ai Qing, was a poet and political radical who, although no activist, was seen as a threat to society. “So I’ve always been involved with human rights issues, not initially out of choice but out of personal experience,” he says.

Many of Ai’s works over a career spanning more than 40 years have been investigations into human rights transgressions, including his own imprisonment by Chinese authorities. But now he has taken his interest a step further by accepting the invitation from UK arts organisations and human rights charities to design a flag to mark the 70th anniversary of the Universal Declaration of Human Rights.

“I don’t recall any kind of symbol for human rights,” he says, sitting at a long wooden table in his studio in Berlin, where he has lived in exile since 2015. “So it was time we gave it one.”

He lays out a series of photographs. They show the muddy footprints of Rohingya refugees who have been forced to flee attacks by Myanmarese soldiers and take refuge in neighbouring Bangladesh.

“These are the footprints of some of the barefooted children, women and young people who we met, who had no shoes,” he says. “Of course it’s very difficult to design something to illustrate such a large, abstract concept. But I thought a footprint relates to everybody who has been forced to flee, whether in Africa, Afghanistan or Bangladesh. There is nothing more human than a footprint.”

The mud-prints have morphed into several versions of a white footprint on a blue background, which form the basis of Ai’s flag. The design is set to be released on 10 December, and UK schools, police forces, faith groups and hospitals will be invited to fly it from their buildings during a seven-day campaign in June.

Facebook Twitter Pinterest ‘It was time to give human rights a symbol’ ... Ai Weiwei. Photograph: Camilla Greenwell

Ai believes that the effects of globalisation have eroded a common understanding of human rights. “Less and less people now talk about human rights since the end of the cold war. They use words like common values instead, so as not to offend the Chinese authorities with whom they want to do business. Increasingly, people are even viewing human rights in a negative way.”

“People in Britain and elsewhere in the better-off world fail to grasp that the way they live can affect the way people elsewhere in the world live,” he continues. “iPhones are made in China because that country joined the capitalism game and plays it very well. But those who make the phones have no basic rights and are modern slaves who end up jumping out of factory windows. People who buy the phones have to have more of a sense of responsibility and engagement.”

Ai took his nine-year-old son with him on a recent trip to Bangladesh – about which he is making a film – just as he has to other investigations, such as to Mexico, to investigate the 43 students who disappeared in a single day in 2014.

“He’s been with me to visit most refugee camps I’ve been to, as well as the poorest ghettos in Mexico, and cartel areas, the island of Lesbos in Greece. I don’t want to teach him anything, but by being exposed to this kind of information he has developed a basic sensitivity of what’s right or wrong. And he sees me arguing a lot with people.”

That morning, the argument was with a Berlin taxi driver on the way to taking his son to school, who told Ai to shut off his mobile phone – he was listening to a message from his mother – because it interfered with the music he was playing on his radio. “He told me to get out of the car, and when I said I wouldn’t he slammed on the brakes and we all fell forward. My son hit his head. He used his vehicle on a public street to express his anger”.

“So you see I am fighting battles wherever I go – including with German people who say I should be grateful to them because I am a refugee, and they paid for my life. This is the mood in Germany right now, the posters I see in the streets saying: ‘We can make our own babies, we don’t need foreigners.’ It’s the mood in much of Europe, including the UK. It’s very scary because this kind of moment is a reflection of the 1930s.”

He is angry and confused about experiencing this sort of hostility in Germany, the country that gave him refuge. He took the first available opportunity to thank its chancellor, Angela Merkel, for her involvement in his release.

“I met her by chance in the Chinese restaurant I go to, which is very close to her flat and where we’ve seen each other several times since. I shook her hand and as it was my birthday she congratulated me. I thanked her for all the effort her government made to bring me out. They were really very supportive.”

Ai’s 4,000m2 studio is 46 steps, or 10 metres, below ground in a former brewery in the north of Berlin. The decision to be subterranean is a very deliberate one, he says. “In my New York studio, I’m also underground. I feel like I have special protection. I have spent years being discriminated against, under surveillance, followed by people undercover, which makes you feel you’re not part of society and you need your own corner. Having once been a way of suppressing my family, being underground has become something positive to me. I need the solitude to work. I need to be separated. It’s a form of self-protection.”