Electronic cigarettes are gaining popularity for a variety of reasons. However, with increased popularity, e-cigarette configuration flaws have raised several issues.
One main issue with the assembly process is due to the hand assembly process. This creates a human error factor in the assembly process. Due to the human error factor, the products currently on the market are of inferior quality and possess unacceptable levels of variability.
Below is a list of several of the issues known and identified in the design of electronic cigarettes presently on the market:                1. The Nichrome wire wound around the wick is assembled by hand, at various tensions and using various numbers of windings. Sometimes there will be four windings around the wick, and sometimes there may be six.        2. The current e-cigarette cartridge assembly has a potential to leak nicotine liquid. This condition will reduce shelf life and convey inferior quality to the consumer.        3. The batteries elicit unacceptable power output variability.        4. The saturated wadding which transfers e-liquid via capillary action to the wick varies in volume.        5. With the vacuum switch located at the ash tip end of most E cigarettes, the user draws air at the mouthpiece through the vacuum switch, across the battery and all of the electronic components, and into the lungs. Thus picking up any vapors that may be present as these components outgas over time.        6. The anode collars on the battery assembly and the heater cartridge assembly are a press fit configuration. The internal wires of the heater cartridge assembly and the internal wires of the battery assembly often exhibit a lack of proper insulation. Should a consumer thread a battery onto a heater cartridge assembly over tightening may occur, resulting in a broken seal between the anode collar and the outer steel casing. When this occurs, continuous over tightening will twist the internal wires of the battery cartridge assembly causing a failure to all components.        7. The electrical contacts in the anode collar assemblies are supported by a silicone insulating tube, which creates a spring action. When a consumer threads the heater cartridge assembly onto the battery assembly, the silicone tube may over compress causing a failure.        8. The heater cartridge assemblies are filled with E liquid by hand, this method can result in an unacceptable level of variability, with respect to the useful life of the product.        9. By its nature and design the current cartridge requires hand assembly, which results in the variability of vapor output.        10. The vacuum switches, poor location, and lack of proper sealing can inadvertently activate the heating coil.        11. Many of the internal electronics have small wires that are hand-soldered to components, resulting in an unacceptable level of variability        12. The current battery design requires two or more hours to recharge.        13. Because this battery lacks a state of charge indicator, it is impossible for a user to accurately predict useful life remaining.        14. When one replaces the heater cartridge assembly a user is throwing away the complete heater assembly. In one embodiment of the new configuration the e-liquid is segregated from the heater assembly to reduce the amount of scrap and waste material.        
These are just to name the basic or most common problems identified with the current products.
USPTO Backgrounds
USPTO Backgrounds