An electronic cigarette, also known as an e-cigarette, personal vaporiser or PV, is an electronic inhaler that vaporises a liquid solution into an aerosol mist, simulating the act of tobacco smoking. Electronic cigarettes are no longer marketed as smoking cessation aids or tobacco replacement in most countries. There may be similarities between conventional and some electronic cigarettes in the physical design and the nicotine release, which may approximate the same amount of nicotine as a conventional cigarette. There are many electronic cigarettes which do not resemble conventional cigarettes at all.
The benefits and risks of electronic cigarette use are uncertain among health organizations and researchers. Limited controlled studies are available due to its recent invention. Laws vary widely concerning the use and sale of electronic cigarettes and accompanying liquid solutions, with pending legislation and ongoing debate.
The earliest electronic cigarette can be traced to Herbert A. Gilbert,who in 1963 patented a device described as “a smokeless non-tobacco cigarette” that involved “replacing burning tobacco and paper with heated, moist, flavored air.” This device heated the nicotine solution and produced steam. In 1967, Gilbert was approached by several companies interested in manufacturing it, but it was never commercialized and disappeared from the public record after 1967.
Hon Lik, a Chinese pharmacist, is widely credited with the invention of the first generation electronic cigarette. In 2000, he came up with the idea of using a piezoelectric ultrasound-emitting element to vaporise a pressurized jet of liquid containing nicotine diluted in a propylene glycol solution. This design produces a smoke-like vapour that can be inhaled and provides a vehicle for nicotine delivery into the bloodstream via the lungs. He also proposed using propylene glycol to dilute nicotine and placing it in a disposable plastic cartridge which serves as a liquid reservoir and mouthpiece. These inventions are the basis of the present-day electronic cigarettes.
The device was first introduced to the Chinese domestic market in May 2004 as an aid for smoking cessation and replacement. The company that Hon Lik worked for, Golden Dragon Holdings, changed its name to Ruyan (如烟, literally “Resembling smoking”), and started exporting its products in 2005–2006 before receiving its first international patent in 2007.