Memory Foam is the abbreviated name for visco-elastic polyurethane foam, and is a soft and flexible foam material, often used for mattresses and other equipment on which a person would sit or lie and require good support.
NASA originally invented memory foam in the 1960s, as they were trying to improve their aircraft seats, but because it proved to be a valuable material, it has become more widespread in its uses and can now be found in many more places. It was in 1991 that that first 'tempur-pedic' mattress came out. The foam was originally known as 'temper foam' because of the fact that is responds to temperature, and in fact this is what helps it mould to the shape of a human body.
Foam Matress Topper
Memory foam is good for chairs and mattresses because it is not as hard on the joints as traditional materials. Your spine is able to align itself as it should do when you lie on memory foam, and will not have to bend at all as your body shape will sink into the foam. This makes the mattresses particularly good for those with orthopaedic problems and complaints. Anyone will find a benefit with it though, and it should reduce the potential for backache.
The problem with memory foam can be the price tag. It costs a little more than other mattresses as it has a higher production cost. It is becoming more affordable though, as technology advances, and is something that is available to most in some form as you can also buy memory foam toppers for beds.
These toppers do the same job as full mattresses, but instead of being a mattress themselves, will just sit atop your existing one. They are made of a thin layer of the visco-elastic polyurethane foam and are just placed under your normal bed sheet, and above your mattress. The toppers are much cheaper than the full mattress as less memory foam has to be used for them, but they are not as good as the full thing as they tend to have around a 2 year life span for staying in the best condition. This is because suppression of the layers will eventually happen, and they will become less flexible.
This can be an excellent material to invest in as has many advantages. Please make sure if you use any memory foam items though, that they are from a reliable source and safety checked. It is actually a combustible substance, and so they do need to be made fire retardant. As long as you buy from a reliable dealer and follow the guidelines, memory foam will serve you well.