Design Features in Multiple Generations of Electronic Cigarette Atomizers

Abstract

The design of electronic cigarette (EC) atomizing units has evolved since their introduction over 10 years ago. The purpose of this study was to evaluate atomizer design in ECs sold between 2011-2017. Atomizers from 34 brands representing three generations of ECs were dissected and photographed using a stereoscopic microscope. Five distinct atomizer design categories were identified in first generation products (cig-a-like/cartomizer) and three categories were found in the third generation. Atomizers in most cig-a-like ECs contained a filament, thick wire, wire joints, air-tube, wick, sheath, and fibers, while some later models lacked some of these components. Over time design changes included an increase in atomizer size; removal of solder joints between wires; removal of Polyfil fibers; and removal of the microprocessor from Vuse. In second and third generation ECs, the reservoirs and batteries were larger, and the atomizing units generally lacked a thick wire, fibers, and sheath. These data contribute to an understanding of atomizer design and show that there is no single design for ECs, which are continually evolving. The design of the atomizer is particularly important as it affects the performance of ECs and what transfers into the aerosol.

Keywords: atomizer; cig-a-like; clearomizer; design features; e-cigarette; electronic cigarette; mods.

Figure 1

General characteristics of four generations of electronic cigarettes (ECs) and atomizing units. The boxes in the column on the right are terms used to describe the three generations of ECs [4]. These terms are based on the external appearance of the EC (cig-a-like and clearomizer) and on whether it is modified (Mod). Each box gives the generation number and the main features of the battery for each generation. The boxes on the left describe the atomizing units found in ECs of each generation. Each box is titled with the overall group classification name (e.g., “3-Piece EC”) followed by a description of the battery, atomizing unit, and fluid reservoir. Blue box = not included in this study; light brown boxes = included in the study; grey box = an emerging class of ECs not included in this study.

Figure 2

Components of the atomizing units across brands and generations of ECs. Tables show the presence or absence of an atomizing unit component in each EC. (A) Major components (filament, thick wire, wire-wire joint, wire-wire-tube joint, air-tube, wick, sheath, fibers) present in ECs. (B) Methods of joining components (wire–wire joint, wire–air-tube joint) and presence or absence of fiber types. Boxes in color = component is present, white boxes = the component is absent.

Figure 3

Anatomy of atomizers from cartomizer style ECs showing three different design categories. (A) Crown 7 Imperial, (B) NJOY NPRO, (C) SafeCig, (D) South Beach Smoke, (E) Liberty Stix Eagle, (F) Smoke 51. The shell, air-tube, filament, wick, sheath, thick wire, and inner and outer fibers are labeled in (A). Design category 1 (A–C), category 2 (D), and category 3 (E–F).

Figure 4

Comparison of atomizers from four brands of first generation cartomizer style ECs across different generations. The internal anatomy of (A) BluCig, (B) BluCig Plus, (C) Mark Ten, (D) Mark Ten XL, (E) V2 Cigs 2012, (F) V2 Cigs 2017, (G) Vuse, and (H) Vuse Vibe. Yellow box in (B) indicates the reservoir, red arrow in (B) indicates the filament, and the blue arrow in (B) indicates the inserts in the BluCig Plus. Design category four (A), and category five (B,G,H).

Figure 5

Comparison of batteries, reservoirs, and atomizing units in different models of second and third generation clearomizer/mod-style ECs. (A) Layout of all batteries and reservoirs used in the study: 1 (Ego C Twist, Kangertech Protank), 2 (Ego C Twist, Aspire Nautilus), 3 (iTaste MVP, Kanger T3S), 4 (Smok Alien, Smok), 5 (Nemesis, Clone), 6 (iPV6X, Tsunami 2.4). (B) Atomizing coils from left to right for 1 (Protank), 2 (Aspire), 3 (Kanger T3S), 4 (Smok). (C) Profile of top of the atomizing coil from Protank. (D) The wick and filament (red arrow) from Protank. (E) Partially built coil from Clone RDA. (F) Fully built Clone atomizer with two coils and wicks. (G) Testing the coils were properly built in the Clone atomizer. (H) Appearance of the coils from Clone atomizer following 60 puffs. (I) Side profile of the Tsunami atomizer. (J) Fully built Tsunami atomizer with wicks. (K) Detail of the wick for the Tsunami atomizer. (L) Cap for covering the Tsunami atomizer.