What do you give Stephen Hawking,, arguably the world's greatest theoretical physicist and cosmologist, for his birthday? That was the challenge put to Mark Champkins, who is doing a spell as inventor in residence at the Science Museum in London. To celebrate the opening of an exhibition about Hawking's life and work and to mark the scientist's 70th birthday, Champkins designed the Black Hole Light, whose spiraling hand-blown fluorescent tubes represent the way light falls into a black hole (Hawking has been instrumental in furthering our understanding of black holes).

The lamp was presented to Hawking's family at the opening of the exhibition entitled Stephen Hawking: a 70th Birthday Celebration last month.

Champkins began the 'daunting' task by talking to two of the curators at the Science Museum who were responsible for putting together the exhibition. 'They were amazingly helpful, explaining a little about Hawking's theories about Black Holes and his work to unite the field of quantum physics with the cosmological,' he says.

He continues: 'They showed me some images of his office, and his most prized objects and awards, along with some models he had made of the way light falls into a black hole. They also directed me to one or two objects in the museum that have relevance to his work.'

Among these objects were Geissler Tubes, which were created by pumping gases into a vacuum tube, and then passing a current through the gas. Champkins was drawn to these as the tubes led to the development of the equipment that was used to discover the electron; but also to the creation of Crookes radiometer. He decided to make a Black Hole Light using a neon tube "the closest thing available to a Geissler tube," adding "I liked the pun, and how it alludes to Hawking radiation.

Champkins initially used coat hangers to create a design he was happy with before making 2D and 3D drawings. 'Finally, I had to track down a glassblower to make it. Eventually I found a great company in the East End who took on the task and made a great job of it,' he says.

Mark Champkins is the first ever inventor in residence at the Science Museum. He is an inventor and designer who gained public recognition after winning the BBC's Dragons' Den programme in 2007 for his Concentrate range - products designed to help children stay focused in the classroom.