E-cigarette testing device

The main testing unit was designed and built by researchers at the ADA Foundation Volpe Research Center (Gaithersburg, MD), in collaboration with researchers at the University of Maryland (College Park, MD) using a custom acrylonitrile butadiene styrene (ABS) enclosure (6”×4”×2”) with a 510 adaptor, a precision wattage meter and power analyzer (Guanglian Town ‘G.T.’ power), and an independent 9 V DC power source. Each component of the main unit was carefully selected from lead-free materials including wires and solder. The main unit has two settings: (1) the e-cigarette user mode and (2) the research mode. In the e-cigarette user mode, power is delivered by a 3.6 V lithium-ion battery similar to how e-cigarette users would use the device as described in e-cigarette online forums. In the research mode, filtered power is delivered by a DC power supply (Model D-612 T, Electro Products). The operator is able to increase or decrease the voltage delivered to the main unit in 0.2 V increments. Real-time voltage (V), current (A), and power (W) are displayed on a LED screen on the main unit. We used a 2.0 ml Vivi Nova tank system with a heating element for the proof-of-principle experiments described here. Based on the resistance of the heating element, we used a conservative power setting of 3.6 V (total of 4.63 W based on P = V² x R) determined by online “vaping power charts” for all of our experiments. Prior to running the e-cigarette, we made sure that the wick was fully saturated with e-liquid by allowing ≥15 min incubation period after each fill.