A month ago, Wu Yulu sold his "son" for 30,000 yuan (US$3,750).

Wu Laowu (the fifth son of the Wu family), is, well, a robot Wu made with his own hands 10 years earlier.

"I couldn't sleep well for several days after selling the child, but I had no other choice. I had to pay off my debts," said Wu, 44, a farmer from Mawu village in eastern Beijing.

On his TV screen, he plays a video of Wu Laowu, serving tea and lighting cigarettes.

In the past 26 years, Wu Yulu has made 25 robots, and "all of them were like my sons."

Wu had a way with machinery and mechanics from childhood.

"Sometimes when people passed by, I would think about the mechanical functions of walking," Wu recalled.

Unfortunately, he could not pursue his passion through textbooks. He was one of five children in the family, and his parents could not support his education after he graduated from primary school in the mid-1970s.

But a lack of formal education did not deter Wu from copying what he called "marvellous human motions."

"At that time, I didn't even  know the term 'robot'," Wu said. "But in my spare time from farming, I tried to collect everything that could be used in those movable things.

"I loved to play with robots. The cleverer they became, the deeper the emotional link I felt to them. Later, I began to call them my sons."

The wire, metal, screws and nails he used came from rubbish sites, or sometimes used parts from farm machinery.

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