The impeller structure and material of a micro centrifugal pump vary depending on the application scenario, working requirements, and fluid properties. The following are some common impeller structures and materials of micro centrifugal pumps:

1. Straight blade impeller: The straight blade impeller is one of the most common impeller structures in a micro centrifugal pump. Its blades are straight or slightly curved, and are suitable for conveying low-viscosity liquids. Plastic materials such as polypropylene (PP) and polycarbonate (PC) are usually used.

2. Curved blade impeller: The blades of the curved blade impeller are curved, which can improve the efficiency and flow of the pump and are suitable for conveying high-viscosity liquids. Metal materials such as stainless steel (SS) and copper (Cu) are usually used.

3. Open blade impeller: There is a certain gap between the blades of the open blade impeller, which can prevent liquid accumulation and blockage between the blades, and is suitable for conveying liquids containing solid particles. Metal materials such as stainless steel (SS) and copper (Cu) are usually used.

4. Hidden blade impeller: The blades of the hidden blade impeller are hidden inside the pump casing, which can reduce the volume and noise of the pump and is suitable for occasions with limited space. Plastic materials such as polyamide (PA) and polystyrene (PS) are usually used.

It should be noted that the material selection of the impeller should be comprehensively considered based on the characteristics, temperature, pressure, corrosiveness and other factors of the fluid to ensure stable and reliable operation and long life of the pump.