Memory foam was developed in 1966 to improve the safety of aircraft cushions.
Memory foam is polyurethane with additional chemicals increasing its viscosity and density. It is often referred to as "visco-elastic" polyurethane foam. Higher-density memory foam softens in reaction to body heat, allowing it to mold to a warm body in a few minutes. A lower-density memory foam is pressure-sensitive.
Why foam memory has memory? Certain chemicals was added to increase weight or density of foam memory. With the addition of these chemicals, a visco-elastic memory foam is created. There are many types of memory foam applied in different industries.
