A look on the other side, or "a note on circular economy, an example”. A health wearables expert looks inside a vape.

Vaping, a practice of inhaling flavoured aerosol is often advertised as a “healthier” alternative to traditional smoking. True enough, the aerosol that comes out of a vape is far less hot than cigarette smoke limiting the heat damage to the lungs. Vapes also come in 0 nicotine variety, meaning a dependency is less likely to form. Now, just how healthy can inhaling “blueberry pancake” flavour be, is an open question. In this little article I will briefly look at another aspect of these devices: their construction and it’s impact on the environment. Unlike the herb and paper cigarettes, vapes are electronic devices and as most of them are disposable, most of them end up in the “General Garbage” bin.

My victim for this dissection is a 15Eur disposable vape, advertised as containing 3500 puffs. This one is a zero nicotine variety. The device is rechargeable and features a UCB-C port and will accept a 5V DC source. I shall not name the brand, this article is not an endorsement of the company or vaping as a practice. With that said, let us make the first cut!

What is immediately apparent is that the device is quite well laid out. Having designed and laid out wearables and other devices myself and having worked with many designers, this is top notch work. The component layout is very pragmatic and there is very little unused volume inside the package. The mouthpiece is silicon and all ports such as charging or the intake port have an arrangement where the USB-C and the electret (more on that later) are seated in a block of a flexible polymer, likely silicone. This is an excellent solution – this allows the polymer block to absorb the manufacturing tolerances of the injection molded case and provides a certain level of waterproofing. Top notch work. Now, we have to go deeper.

The battery, upon close inspection is size 282215 – 28mm long, 22mm wide and 15mm thick. It claims to provide 2.4wH at 3.7V, or 650mAh. This is an impressive battery, some of our wearable devices make due with a third of that! The PCB is white which is a bit puzzling – in general you wouldn’t bet on the average user ever looking inside, and traditionally a white soldermask cost more than the traditional green one. About 60% of the internal volume is taken up by? a soaked foam liquid container. The heater is placed right in middle of that container.

Looking closer at the board, we can see some passives, lots of LEDs, a transistor and a 14C1N chip. This chip is an overvoltage protection IC used to protect the battery. Often LiPo batteries would have this on the battery itself but given the nature of the device it’s practical to place it on the PCB. A LiPo should not be charged by 5V directly – never more than 4.2V. It’s unclear from the 14C1N datasheet how the voltage is lowered but there are ways from diodes (there is one on the board), voltage dividers, to this being a special version of 14C1N that limits voltage output to 4.2V. Either way, schematic capture is not the goal of this article.

Lastly, possibly the most interesting bit is the little sensor that triggers the heater when it detects a puff. The sensor is referred to as an electret, sometimes as an electret microphone. Fear not, this particular microphone cannot capture sounds, it’s a membrane that collapses when the pressure inside the vape’s case drops. However, a typical electret only has 2 wires, this one has 5. After a brief Google search, turns out, this electret comes with a little ASIC (Application Specific Integrated Circuit), a custom silicon solution that monitors the electret and triggers the heater. Impressive stuff.

?????????????? So what do we see in that device? A well designed system, with some valuable and very reusable components that will most likely end up in the landfill. Just imagine the damage it does to environment!? Take note of that, dear reader, and please commit to throwing vapes into designated recycling containers. Waste not, want not, as they say. As for myself, I intend to reuse the battery as well as the USB-C port. What for? Watch this space to find out!