2018 Volume 61 Issue 3 Pages 119-130
In materials processing using plasma in contact with liquid, plasma plays an important role as a trigger to promote primary processes at the plasma/liquid interface. However, direct effects such as radicals from plasma vanish after traveling a few or a few 10 nm from the plasma/liquid interface. The rest of the processes in liquid proceed only deep inside the liquid where the direct effects of plasma are no longer expected. This situation can be regarded as robustness in the process. However, at the same time, it has a negative aspect of poor controllability by plasma. In other words, the factor of “the unique to plasm” governs only the limited part of a whole process. In this paper, we survey recent research activities on materials processing using plasma in contact with liquid from the view point mentioned above, and discuss why we use plasma.