A Piezoelectric-Driven Rock-Drilling Device for Extraterrestrial Subsurface Exploration

Figure 13

The drilling experiment results of the rocks with different hardness grades. (a) Red brick. (b) Sandstone. (c) Melaleuca stone. (d) Marble. (e) Green rock. (f) Granite.

(a)

(b)

(c)

(d)

(e)

(f)