Electronic cigarettes, often referred to as e-cigarettes or vapes, are battery-operated devices designed to deliver an aerosol, typically containing nicotine and flavorings, to the user by heating a liquid solution (e-liquid).
Operating Principle
The core function of an e-cigarette involves a battery providing power to a heating element (atomizer). This atomizer vaporizes the e-liquid held in a reservoir or cartridge. The user then inhales this aerosol, mimicking the act of smoking.
Key Components
- Battery: Usually a rechargeable lithium-ion battery, this is the power source. Its capacity and output can vary significantly between device types.
- Atomizer: Contains a heating coil (typically made of Kanthal, stainless steel, nickel, or titanium) and a wicking material (often cotton) that draws e-liquid to the coil. When heated, the coil aerosolizes the e-liquid.
- E-liquid (Vape Juice): This solution primarily consists of:
- Propylene Glycol (PG): A carrier for flavor and nicotine, provides a “throat hit.”
- Vegetable Glycerin (VG): A thicker substance that produces more vapor.
- Nicotine: Available in various concentrations, including nicotine-free options. It is an addictive substance.
- Flavorings: Food-grade flavorings are used to create a wide variety of tastes.
- Cartridge or Tank: A container that holds the e-liquid.
- Mouthpiece (Drip Tip): The part through which the user inhales the aerosol.
Types of Electronic Cigarettes
E-cigarettes have evolved into several general categories:
- First-generation (Cigalikes): Designed to resemble traditional cigarettes. Often disposable or use replaceable pre-filled cartridges.
- Second-generation (Vape Pens): Larger than cigalikes, with a pen-style form factor. Usually feature a rechargeable battery and a refillable tank.
- Third-generation (Mods): More advanced and customizable devices. These include “box mods” or “tube mods” offering features like variable wattage/voltage, temperature control, and compatibility with various atomizers (e.g., RDAs, RTAs, sub-ohm tanks).
- Pod Systems: Compact, user-friendly devices that utilize “pods” – small, often disposable or refillable cartridges containing e-liquid and an integrated coil. Popular for their portability and ease of use, particularly with nicotine salt e-liquids.
Aerosol and Constituents
The aerosol produced by e-cigarettes is not merely water vapor. It contains the vaporized constituents of the e-liquid, including nicotine (if present), PG, VG, flavorings, and potentially other chemicals and trace metals. The exact composition can vary depending on the device, e-liquid, and user behavior. While generally considered to contain fewer toxic substances than combustible cigarette smoke, the long-term health effects of inhaling e-cigarette aerosol are still an area of active research.
