**Abstract**

From an engineering approach, rare earth elements (REE) have the extra potential to modify modern engineering in an extraordinary way. Their peculiar optical, mechanical, electronic, and magnetic properties have been used for years and even open up wider possibilities for using rare earth elements. With advances in all fields of engineering, it is predictable that the rare earth elements will play a crucial role. The use of the rare earth elements permits many new advances, including digital and magnetic technologies operating at reduced energy consumption, higher efficiency, miniaturization, speed, and durability. The REEs are particularly crucial components in clean energy applications, which is especially important in the fight against global warming. For these reasons, the rare earth elements will become essential components in the technological revolution in the second quarter of the twenty-first century.

**Keywords:** REE engineering, permanent magnets, clean energy, phosphors, bioimaging
