Research by Thomson Reuters shows that China – with over 300 million smokers – is the front runner in the manufacture and development of so-called e-cigarette technology, while new versions being patented include a “pay as you go” computer-assisted device and others that can deliver caffeine instead.

Tobacco giant Philip Morris International describes an e-cigarette that would allow users to “pay as you go” by buying a certain number of doses via computer application connected to their e-cigarette. Customers could also program the device to shut off after a certain number of puffs per use to help limit intake.

Other smaller players aim to deliver doses of caffeine and other additives instead of nicotine.