Molecular materials having a spin transition have been studied since the `30s. Since then, more than 300 materials have been synthesised by several physicochemic techniques.

For using the physical properties of inorganic and metalorganic materials, it is possible to create a thin film on a substrate and micro-structuring a component. However, such technique is very difficult often failed. This is due to the incompatibility between deposition techniques and the spin transition (which is very sensitive to crystal network).

Thus, no available solutions are satisfying for structuring and keeping safe as well the spin transition property of a molecular material.