Construction of electronic cigarettes
An electronic cigarette is a handheld battery-powered vaporizer that simulates smoking, but without tobacco combustion. E-cigarette components include a mouthpiece, a cartridge, a heating element/atomizer, a microprocessor, a battery, and some of them have an LED light on the end. An atomizer consists of a small heating element, or coil, that vaporizes e-liquid and a wicking material that draws liquid onto the coil. When the user inhales, a flow sensor activates the heating element that atomizes the liquid solution; most devices are manually activated by a push-button. The e-liquid reaches a temperature of roughly within a chamber to create an aerosolized vapor. The user inhales an aerosol, which is commonly but inaccurately called vapor, rather than cigarette smoke. Vaping is different from smoking, but there are some similarities, including the hand-to-mouth action of smoking and an aerosol that looks like cigarette smoke. The aerosol provides a flavor and feel similar to tobacco smoking. There is a learning curve to use e-cigarettes properly. E-cigarettes are cigarette-shaped, and there are many other variations. E-cigarettes that resemble pens or USB memory sticks are also sold that may be used unobtrusively.
There are three main types of e-cigarettes: cigalikes, looking like cigarettes; eGos, bigger than cigalikes with refillable liquid tanks; and mods, assembled from basic parts or by altering existing products. Cigalikes are either disposable or come with rechargeable batteries and replaceable nicotine cartridges. A cigalike e-cigarette contains a cartomizer, which is connected to a battery. A "cartomizer" or "carto" consists of an atomizer surrounded by a liquid-soaked poly-foam that acts as an e-liquid holder. Clearomizers or "clearos", not unlike cartotanks, use a clear tank in which an atomizer is inserted. A rebuildable atomizer or an RBA is an atomizer that allows users to assemble or "build" the wick and coil themselves instead of replacing them with off-the-shelf atomizer "heads". The power source is the biggest component of an e-cigarette, which is frequently a rechargeable lithium-ion battery. In the United States, the voluntary industry standard, UL 8139 Standard for Safety for Electrical Systems of Electronic Cigarettes and Vaping Devices, covers battery-operated electrical systems for electronic cigarettes and vaping devices.
As the e-cigarette industry continues to evolve, new products are quickly developed and brought to market. First-generation e-cigarettes tend to look like traditional cigarettes and so are called "cigalikes". Most cigalikes look like cigarettes but there is some variation in size. Second-generation devices are larger overall and look less like traditional cigarettes. Third-generation devices include mechanical mods and variable-voltage devices. The fourth-generation includes sub-ohm tanks and temperature control devices. The voltage for first-generation e-cigarettes is about 3.7 and second-generation e-cigarettes can be adjusted from 3 V to 6 V, while more recent devices can go up to 8 V. The latest generation of e-cigarettes are pod mods, which provide higher levels of nicotine than regular e-cigarettes through the production of aerosolized protonated nicotine.
E-liquid is the mixture used in vapor products such as e-cigarettes and usually contain propylene glycol, glycerin, nicotine, flavorings, additives, and differing amounts of contaminants. E-liquid formulations greatly vary due to rapid growth and changes in manufacturing designs of e-cigarettes. The composition of the e-liquid for additives such as nicotine and flavors vary across and within brands. The liquid typically consists of a combined total of 95% propylene glycol and glycerin, and the remaining 5% being flavorings, nicotine, and other additives. There are e-liquids sold without propylene glycol, nicotine, or flavors. The flavorings may be natural, artificial, or organic. Over 80 chemicals such as formaldehyde and metallic nanoparticles have been found in the e-liquid. There are many e-liquids manufacturers in the US and worldwide, and more than 15,500 flavors existed in 2018. Under the US Food and Drug Administration rules, e-liquid manufacturers are required to comply with a number of manufacturing standards. The revision to the EU Tobacco Products Directive has some standards for e-liquids. Industry standards have been created and published by the American E-liquid Manufacturing Standards Association.
Uses
Function
An e-cigarette is a handheld battery-powered vaporizer that simulates smoking, but without tobacco combustion. Once the user inhales, the airflow activates the flow sensor, and then the heating element atomizes the liquid solution. The different kinds of trigger sensor or sensors used are acoustic, pressure, touch, capacitive, optical, Hall Effect or electromagnetic field. Most devices have a manual push-button switch to turn them on or off. E-cigarettes do not turn on by trying to "light" the device with a flame.The e-liquid reaches a temperature of roughly 100-250 °C within a chamber to create an aerosolized vapor. Variable voltage devices can raise the temperature.
A glycerin-only liquid vaporizes at a higher temperature than a propylene glycol-glycerin liquid. Rather than cigarette smoke, the user inhales an aerosol, commonly but inaccurately called vapor. E-cigarettes do not create vapor between puffs.
E-cigarettes are also used by some people as a smoking cessation aid. A Cochrane review found that nicotine e-cigarettes can help people stop smoking and may be more effective than nicotine replacement therapy and this use is supported by public health guidance in England. Some users also use electronic nicotine delivery systems to vape cannabis products, including cannabidiol or tetrahydrocannabinol oils and e-liquids that are compatible with ENDS devices. Some people use e-cigarettes while continuing to smoke conventional cigarettes, for example during quit attempts or in situations where smoking is restricted.
In the United Kingdom, guidance from the National Institute for Health and Care Excellence notes that, as of February 2025, no nicotine-containing e-cigarettes were licensed as medicines for smoking cessation by the Medicines and Healthcare products Regulatory Agency, and products not licensed as medicines cannot be marketed by manufacturers for stopping smoking; however, UK public health guidance distinguishes between the harms of combustible tobacco use and the use of smoke-free nicotine products, noting that vaping is less harmful than smoking and may support smoking cessation when smokers switch completely.
Perception
Vaping is different from tobacco smoking, but there are some similarities with their behavioral habits, including the hand-to-mouth action and a vapor that looks like cigarette smoke. E-cigarettes provide a flavor and feel similar to smoking. A noticeable difference between the traditional cigarette and the e-cigarette is sense of touch. A traditional cigarette is smooth and light but an e-cigarette is rigid, cold and slightly heavier. Since e-cigarettes are more complex than traditional cigarettes, a learning curve is needed to use them correctly.Compared to traditional cigarettes, the general e-cigarette puff time is much longer, and requires a more forceful suction than a regular cigarette. The volume of vapor created by e-cigarette devices in 2012 declined with vaping. Thus, to create the same volume of vapor increasing puff force is needed. Later-generation e-cigarettes with concentrated nicotine liquids may deliver nicotine at levels similar to traditional cigarettes. Many e-cigarette versions include a power control to adjust the volume of vapor created. The amount of vapor produced is controlled by the power from the battery, which has led some users to adjust their devices to increase battery power. Larger percentages of glycerin in e-liquid also increase vapor production.
Construction
E-cigarettes come in many variations, such as cigarette-shaped, pen-shaped, and tank-shaped styles. Some e-cigarettes look like traditional cigarettes, but others do not. There are three main types of e-cigarettes: cigalikes, looking like cigarettes; eGos, bigger than cigalikes with refillable liquid tanks; and mods, assembled from basic parts or by altering existing products.E-cigarette components include a mouthpiece, a cartridge, a heating element/atomizer, a microprocessor, a battery, and some have a LED light on the end. E-cigarettes are sold in disposable or reusable variants. Most versions are reusable, though some are disposable. They range in cost from under $10 to over $200. An entry-level reusable e-cigarette costs around $25.
Disposable e-cigarettes are discarded once the liquid in the cartridge is used up, while rechargeable e-cigarettes may be used indefinitely. Even with rechargeable cigarettes, there is a risk of littering. There are thoughts on how to prevent pods from ending up in the environment. One piece devices are normally disposable.
E-cigarettes are typically designed as one, two, three or multiple pieces. A disposable e-cigarette lasts to around 400 puffs. Reusable e-cigarettes are refilled by hand or exchanged for pre-filled cartridges, and general cleaning is required. A wide range of disposable and reusable e-cigarettes exist. Disposable e-cigarettes are offered for a few dollars, and higher-priced reusable e-cigarettes involve an up-front investment for a starter kit. Some e-cigarettes have a LED at the tip to resemble the glow of burning tobacco. The LED may also indicate the battery status. The LED is not generally used in personal vaporizers or mods.
First-generation e-cigarettes usually simulated smoking implements, such as cigarettes or cigars, in their use and appearance. Later-generation e-cigarettes often called mods, PVs or APVs have an increased nicotine-dispersal performance, house higher capacity batteries, and come in various shapes such as metal tubes and boxes. They contain silver, steel, metals, ceramics, plastics, fibers, aluminum, rubber and spume, and lithium batteries. A growing subclass of vapers called cloud-chasers configure their atomizers to produce large amounts of vapor by using low-resistance heating coils. This practice is known as cloud-chasing. Many e-cigarettes are made of standardized replaceable parts that are interchangeable between brands. A wide array of component combinations exists. Many e-cigarettes are sold with a USB charger. E-cigarettes that resemble pens or USB memory sticks are also sold for those who may want to use the device unobtrusively.
The increasing numbers of new vaping products combined with unrelated functions attest to a clear trend toward customization of e-cigarettes. It seems that experienced users like to adopt the e-cigarette to their needs, leading to e-cigarettes with adjusted airflow inlet using atomizer heads with different sized air holes. This is applied in the most recently introduced models, which are activated by a pressure difference when the user inhales from the e-cigarette, avoiding pressing a button to heat the device. Other interesting new e-cigarette-like devices provide a combined function with other electronic products such as a Bluetooth e-cigarette, which combines vaping with listening to music or calling friends and another device can be used both as e-cigarette and mobile phone.
Smartphone applications were introduced that track the number of e-cigarette puffs taken, calculate cost savings and increased life expectancy, and have features such as auto-shut down and password protection safety. In line with this, Philip Morris International has filed a patent for an e-cigarette that is Wi-Fi connected, and thus would be able to connect to other devices. This device could potentially synchronize to a smartphone application that is intended to help people quit smoking, and carefully track their progress. A similar product is the Vaporcade Jupiter, a "cellular vaporizer," combining a smartphone with an e-cigarette. This allows the user to monitor the e-cigarette use, the e-liquid remaining, and the flavor used.