Biomaterials for Bone Regeneration

206 Biomaterials for Bone Regeneration

modi cation apply cold or non-thermal plasmas. Therefore in this chapter,

we will limit the content to this type of plasma source.

Cold plasmas are generated by an electrical gas discharge. A strong electric

 eld is applied to a neutral gas, resulting in ionization in the gas volume. The

charged particles formed are accelerated in the electrical  eld and, in partic-

ular, the electrons are in uenced by the  eld and gain most energy due to

their light mass. The electrons achieve high temperatures (100 000–1 000 000

K), while by collisions with the background gas the heavy ions exchange their

energy and thus remain cold. Radicals, which play an important role in the

chemical activity of the plasma, ...