The general technique is placing the biological scaffold into a supersaturated solution of a specific composition, and the nucleation and grow of mineralized particles and thickness of mineralized layer on the surface of the scaffold can be controlled or adjusted. However,  only a single type of crystals and same density of mineralized layer can be obtained and cannot extents the applications in the field of biomedical researches and clinical implants.   Here we provide a method and special designed device for manufacturing a new type of mineralized scaffold. A micro-environment with a concentration gradient by changing the internal chamber space of the device is provided. The formation of mineralized layers with different densities and diffusions on the surface of the biological scaffold, so that the distribution concentration and the size of mineralized particles can be controlled and formed on the surface of the biological scaffold.

Diffusion device contains a controllable double-cavity structures. Different types of tissue engineering scaffolds or membrane materials can be placed within clapboard between the two side cavities. The space between both sides of the chamber changes oppositely, which can create concentration gradient together with a diffusion gradient of the solution on both sides when mineralization proceeds. A magnet is installed on the side of the cavity clapboard, and the clapboard angle can be adjusted freely and easily outside without contact or open the device. The surface processing technology with concentration gradient can directly provide a continue changing surface, which can reduce the possible leakages of the interval concentration.

Adjustable concentration gradient is created for continue changing surface. It can be applied in medical era for development such as concentration and dosage effect, the bio-chemical molecular concentration and/or softness of surface, or biological molecular coating surface, the physical/ mechanical properties of the inorganic particles on cells/ materials, and the antibacterial test.