There are several US patents for ‘glow stick’ type devices by various inventors most related to the US navy. The first and original was actually invented as early as 1964. In 1976 the patent for the Chemiluminescent Lighting Device was registered. Since that time the simple and safe to use devices have become widely used in many areas. You probably most commonly see them in bars and night-clubs however they are regularly used by emergency services on land and sea. The original stick design was born out of the need to have a light source without fire, heat or batteries and was readily used by land and marine forces and soon became popular amongst civilian and commercial use.
Without fire or battery, how do they work?
In all cases atoms are excited to emit light photos. With batteries and other sources of electric currents, light photons are emitted due to heat (incandescence) from the filament of a light bulb, often intensified with reflective backing and magnified with glass or plastic. From dancing around and having fun at Sydney hostels right through to exploring caves, the glow stick is an amazing product.
The most extreme form of light compared to incandescence is that of lasers. Laser light is emitted by machinery that concentrates the emission of light with powerful stimulation, more costly however highly intensified.
The third type of light is chemiluminescent light, where photons are released by a chemical reaction. This is the light produced by your everyday glow stick or glow products.
How do the devices and the chemical reaction work?
We know that the devices release light and we can that light comes from a liquid inside. Actually there are 2 chemicals present. Although these chemicals have been adjusted and refined from the early days of military use, and now they are non-toxic and non-flammable, a measure of care is always recommended. Just as there is a reaction when you drop a mentos sweet into diet coca-cola, there is a chemical reaction when the two chemicals are mixed inside the stick.
Normally one of the chemicals is sealed inside a very thin glass like tube inside the outer chemical and that is why you normally need to bend the stick to start it. The glass container carrying one of the chemicals will shatter and allow the solutions to mix. As with all chemical reactions the level of heat will influence the light emitted from a glow stick. If you have a warm stick it will emit light brightly for a shorter period of time, and a frozen stick will emit light for a long period of time but at much lower levels.
Practical Uses
Most of us, except those of us who regularly go camping think of glow sticks as only party devices. The reality is that they can be used in a number of serious and important situations. And due to relatively cheap cost, the recyclable nature makes them an excellent tool for safety and rescue situations as mentioned above.
Despite them being cheap they have an extremely long shelf life. Kept in a cool and dry place they can last up to 4 years. Now you are thinking that there are many safe uses and are a much safer option than candles stored in your home in the case of a black out. Even if you are at a backpackers in Sydney just wanting to look through your bag without a light, this invention is amazing.