China sets the pace in global race to develop e-cigarette technology

Makers of electronic cigarettes are racing to design and buy variations of a technology triggering a billion-dollar boom and prompted a backlash from health officials worried by the impact of the smokeless devices.

China, with more than 300 million smokers, is the front runner in the development of e-cigarette technology, while versions being patented include a "pay as you go" computer-aided device and others that deliver caffeine.

In 2005 just eight e-cigarette inventions were described in published patents. By 2012 the figure had jumped to 220 and by last year there were 500 inventions, according to an analysis by the IP & Science business of Thomson Reuters. So far this year the total has reached 650.

The original technology, involving battery-powered heating systems that vaporise nicotine-laced liquid, is credited to Hon Lik, a Chinese medical researcher with a 20-a-day habit, in 2003.

His invention has since become so popular that the market is now estimated to be worth US$3.5 billion. Both big tobacco firms and small entrepreneurs are racing to find new ways to "vape", which is a verb suddenly so mainstream the Oxford English Dictionary named it the 2014 Word of the Year.

Imperial Tobacco last year snapped up the patents owned by the company Hon co-founded in a deal worth US$75 million, and is suing rivals for alleged patent infringements.

Part of the rush can be explained by the prospect of stiffer regulation on e-cigarettes after the World Health Organisation said it wanted to see this, along with bans on indoor use, advertising and sales to minors.