Experiments with Co2, Water Vapour, and Lasers

Sci-Fi Laser Blaster

This page is about experiments with Co2 Gas, Water Vapour, and Lasers. Check out the main project index for the rest.

I will only be using a low power laser pointer for this project, so we need some mist/smoke/vapour in order to shine the laser through to make the beam visible. There is a YouTube video about this section.

Most low power lasers that you can buy cheaply are rated at less than 1mW (one-thousandth of a Watt). This is still quite bright because the light is polarised, so it is concentrated in one direction. Higher power lasers with a visible beam can be dangerous because they can burn things. However, you should still be careful with low power lasers – if you look directly into the beam you can damage your eyesight.

In nightclubs where laser lightshows are present, typically there are smoke machines which allow the laser beam to be visible as it lights up the smoke particles in its path. In the video above I talk about using Co2 to make a jet of vapour, however there are some issues with this – mainly the valve and canister gets very cold because Co2 is a refrigerant, and this method involves high pressures which can be dangerous. Also the small Co2 canisters don’t have much gas in them, so you need to keep swapping them out.

Pictured below is an ultrasonic mister/nebuliser/atomiser. This is electronically powered and uses ultrasound to break up the surface of normal water to produce a dense vapour. This ones runs on 24V @ 1A, however I will be using a 12-24V DC-DC converter to power it from 12V @ 2A.

There are still some safety issues with water vapour – bacteria can grow in water, so you need to be careful that the water is clean, or that you chlorinate the water (visit a pool or spa shop), so that you don’t spread bacteria into the air. Legionnaires disease can be fatal, this this is quite important.

I need to think some more about the mechanism for dispersing the vapour from the front of a blaster prop, and this will be detailed in the next part. Here are some pictures of my low powered laser pointer shining through a small amount of vapour.

Check out the next part.