A competitor scrambles in the mud under barbed wire during the Tough Guy Challenge 2009 at South Perton Farm on February 1, 2009 in Wolverhampton, England. The biannual event to raise cash for charity challenges thousands of international competitors to run through a gruelling set of 21 obstacles including water, fire and tunnels after a lengthy run at the start. (Photo by Christopher Furlong/Getty Images)

Farmers harvest cocoa fruits at a plantation in Gantarang Keke Village, South Sulawesi, Indonesia May 8, 2015. Sulawesi is at the heart of Asia's largest cocoa producing region, and is where some international confectioners are looking to boost output to feed growing demand for chocolate in the region. (Photo by Yusuf Ahmad/Reuters)

In this photo posted on Twitter, Sunday, May 3, 2015, and provided by NASA, Italian astronaut Samantha Cristoforetti sips espresso from a cup designed for use in zero-gravity, on the International Space Station. Cristoforetti, the first Italian woman in space, fired up the first espresso machine in space, which uses small capsules, or pods, of espresso coffee. (Photo by AP Photo/NASA)

Dragon boat racers prepare for the fancy dress race on July 5, 2015 in Hong Kong, Hong Kong. The Hong Kong Dragon Boat Carnival will be staged from 3 July 2015 (Friday) to 5 July 2015 (Sunday). The carnival featured two key programmes: the CCB (Asia) Hong Kong International Dragon Boat Races in Victoria Harbour and the San Miguel BeerFest at the UC Centenary Garden in East Tsim Sha Tsui. (Photo by Taylor Weidman/Getty Images for Hong Kong Images)

Damaged vehicles sit on Yeongjong Bridge in Incheon, South Korea, Wednesday, February 11, 2015. Two people were killed and at least 42 were injured on Wednesday after a pileup involving about 100 vehicles in foggy weather on the bridge near the Incheon International Airport, South Korean officials said. (Photo by Suh Myung-gon/AP Photo/Yonhap)

A solar-powered plane takes off from Jiangbei International Airport in southwest China's Chongqing Municipality, Tuesday, April 21, 2015. The Solar Impulse 2 departed Chongqing on Tuesday for a 1190-kilometer (642-mile) flight to the city of Nanjing in eastern China, the sixth leg of its around-the-world flight. (Photo by Chinatopix via AP Photo)

The world's first 3D printed car – the Stratti – was built in just 45 hours at the International Manufacturing Technology Show which took place between September 8 – 13, 2014. The Strati, which is Italian for layers, has a chassis body made of one solid piece and has a top speed of 40mph. The tyres, seats, wheels, battery, wiring, suspension, electric motor and window shield of the revolutionary vehicle were made using conventional methods. (Photo by Barcroft Media/ABACAPress)

“A robot suit that can help the elderly or disabled get around was given its global safety certificate in Japan on February 27, 2013, paving the way for its worldwide roll-out”. Photo: Robot suit “Hybrid Assistive Limb (HAL)” worn by a man developed by University of Tsukuba is seen lifting a 30kg weight during 2005 International Robot Exhibition on November 30, 2005 in Tokyo, Japan. By wearing the power suit, it makes it easier to move and lift heavy things. (Photo by Koichi Kamoshida)