Zhang Yali, 49, tests a giant bicycle designed and made by him and his friends outside a rented warehouse in Jilin, Jilin province December 25, 2011. The 3.2-metre-high and 5.5-metre-long three-seated giant bicycle, weighing over one tonne, cost Zhang more over 20,000 yuan (3,156 USD). Zhang spent two months making this bike as a gift for his son, a 25-year-old part-time cartoonist currently living in Shenzhen, Guangdong province. According to Zhang's family, they were planning to ride this bike from Jilin to Shenzhen, local media reported.

*NO SALES TO ALL FINANCIAL, BANKING AND INSURANCE INDUSTRIES WORLDWIDE UNTIL 12 JULY 2018* Zhang Wuyi sits in his newly made multi-seater submarine at his new workshop near an artificial pool in Wuhan, Hubei province, November 14, 2012. Zhang, a 37-year-old local farmer, who is interested in scientific inventions, has independently made seven miniature submarines with several fellow engineers, one of which was sold to a businessman in Dalian at a price of 100,000 yuan ($15,855) last October. The submarines, mainly designed for harvesting aquatic products, such as sea cucumber, have a diving depth of 20-30 metres (66-98 feet), and can travel for 10 hours, local media reported. REUTERS/Stringer

Zhao Xiuguo drives a homemade model of Formula One car in Tangshan, Hebei Province, some 180km (113 miles) east of Beijing July 21, 2006. Zhao Xiuguo and his brother Zhao Xiushun built the car from scrap metal and said that they wanted to design and build the first Formula One racecar in China.

Su Daocheng rides his home-made mechanical horse vehicle on a street in Shiyan, Hubei province January 18, 2015. Su spent 2 months making this 1.5 metre high and 2 metre long horse, which weighed 250 kilograms with 4 legs and 2 supportive wheels, local media reported. REUTERS/Stringer

Farmer Wu Yulu drives his rickshaw pulled by a his home-made walking robot near his home in a village at the outskirts of Beijing January 8, 2009. This robot is the latest and largest development of hobby inventor Wu, who started to build robots in 1986, made of wire, metal, screws and nails found in rubbish sites.

Li Jingchun (top L), a 58-year-old farmer, works with his family members on his home-made aircraft on top of his house in Xiahe village located in Shenyang, Liaoning province February 28, 2012. The 5m long, 1.5m wide plane, mostly made of recycled iron plates, cost the aircraft enthusiast and his family two years and more than 40,000 yuan ($6,349), according to local media.

A Chinese inventor, Yang Zongfu celebrates on his six-ton (5,443 kg) ball container named Noah's Ark of China after he succeeds in a series of tests of the vessel in Yiwu, Zhejiang province, August 6, 2012. According to local media, Yang spent two years and 1.5 million RMB (235,585 USD) to build this four-metre diameter vessel, which has been tested capable of housing a three-person family and sufficient food for them to live in 10 months. The vessel was designed to protect people inside from external heat, water and external impact.

Chinese inventor Tao Xiangli controls his self-made humanoid robot with a remote controller as he poses with it during a photo opportunity at his house located in a old residential area in Beijing August 8, 2013. The self-taught Chinese inventor built the home-made robot, named 'The King of Innovation', out of scrap metal and electronic wires that he bought from a second-hand market. Tao completed his creation in less than a year, with costs of production and living expenses amounting to 300,000 yuan ($49,037). However, the robot, which measures 2.1 metres (6.9 feet) in height and 480 kg (1058 lbs) in weight, turned out to be too tall and heavy to walk out of the front door of his house. It can perform simple movements with its hands and legs and also mimic human voices. REUTERS/Kim Kyung-Hoon

Liu Fulong tests his home-made wooden electronic vehicle in Shenyang, Liaoning province, October 30, 2014. The vehicle Liu created weighed more than 200 kilograms, has a top speed of up to 30km/h and the power capacity to travel up to 20km after one charge, according to local media. Picture taken October 30, 2014.

A Chinese flag is seen as Liu Wanyong performs on his invention, an improvised bicycle which is held afloat by plastic tubes, in Zhenning, Guizhou province, August 29, 2013. Liu, 52, is a grassroots inventor who mostly creates things that are related with the traditional village lives of the ethnic minority people in Guizhou. Picture taken August 29, 2013. REUTERS/Stringer

Guo, a farmer in his 50s, drives his home-made scale replica of a Lamborghini with his grandson on a street in Zhengzhou, Henan province February 19, 2014. Guo spent 6 months and about 5,000 yuan (821 USD) to make the 2-metre-long, 1 metre-wide "Lamborghini" as a toy for his grandson. The replica, mainly made of scrapped metals and parts from electricity bicycles, bears five sets of batteries and can travel as far as 60 km (37 miles) when fully charged, local media reported. Picture taken February 19, 2014.

Zhang Haiyong adjusts his home-made plane in Binzhou, Shandong province, October 17, 2013. Zhang, 30, spent five months and more than 8,000 yuan ($1312.80) to build the plane made from steel bars, canvas and used car engines. During test flights, the plane was able to fly two to three metres above ground during, local media reported. Picture taken October 17, 2013.

Tao Xiangli stands on his homemade submarine in a courtyard in Beijing July 10, 2008. The amateur inventor says his submarine is made from old oil barrels but fully functional with a periscope, depth control tanks, electric motors and two propellers. Tao plans to test it soon. Reuters/Reinhard Krause

Ding Shilu, an automobile mechanic, carries out a test-flight for his home-made aircraft at a frozen reservoir in Shenyang, Liaoning province February 25, 2011. The aircraft which weighs about 130 kg (287 lbs) and is made of recycled materials including three motorbike engines and plastic cloth, costs about 2600 yuan ($395), local media reported. REUTERS/Stringer

Local farmer Shu Mansheng hovers above the ground in his self-designed and homemade flying device during a test flight in front of his house in Dashu village on the outskirts of Wuhan, Hubei province September 21, 2011. The round steel flying device, which cost more than 20,000 yuan ($3,135), is the fifth model made by Shu, a junior middle school graduate. It measures around 5.5 meters (18 feet) in diameter, and is powered by eight motorcycle engines. Shu managed to hover for 10 seconds at about 1 metre (3.3 feet) above ground during a recent test flight. REUTERS/Stringer

Xu Zhiyun (L), 60, drives his home-made motorised mini-vehicle along a street in Shanghai December 9, 2014. Xu spent over two years to complete the mini-vehicle measuring 60cm (24 inches) by 35cm (14 inches) by 40cm (16 inches), which has a 77cc engine and five gear ranges.

A man surnamed Zhang sits in his home-made armoured vehicle look-alike on a street in Shenyang, Liaoning province, November 12, 2014. A man surnamed Zhang and his friends converted two cars into these two vehicles, for his son, and will be displaying them on show at a local park. The cannons on the vehicles can fire paintballs and smoke shells, local media cited Zhang as saying. Picture taken November 12, 2014. REUTERS/Stringer

A man drives a self-made replica of a sports car with his family in Zhuzhou, Hunan Province, China, May 3, 2016.

A friend of Zhu Yue walks by a full-scale replica of the Airbus A320 plane that they are building, in Kaiyuan, Liaoning province, China April 3, 2018.

A homemade submarine named "Shenlong-3" made by Zhang Junlin, a 62-year-old retired prison guard, is pictured at a factory in Fuyang, Anhui province December 20, 2014. Zhang spent 2 years with his team to build the 15-metre-long (49-ft) submarine, which weighs about 25 tons and can hold up to 20 people. The submarine, the third one made by Zhang and his team, will be put under a test run in water soon, according to local media.

A woman rides an unicycle at a park in Shanghai February 28, 2004. The unicycle was designed several years ago by Chinese inventor Li Yongli who called it "the number one vehicle in the world".