Some recent news on microstructure design:

Article about MIT on CNN

Article about Boeing on Forbes

Microstructure determines material properties. With 3D printing technology, we can fabricate tailored microstructure which is optimal for specific purpose. More over, the microstructure can vary in geometry and density throughout the structure, thus allowing boundless exotic functionalities.

Refer to this video for an example.

Below are samples of 3D printed femur bone and airfoil generated using TopShape.