Figure 9.

Hard and soft energy generators. (a) Rigid versus soft ocean wave energy converters (WEC). In the rigid generator steel and concrete dominate as used materials, whereas for the soft generator one may deploy rubber tubes into the ocean to be deformed by waves. (b) Experimental rubber tube system under water, showing the deformation by caused by waves Reprinted with permission.⁶⁴ Copyright 2012, SPIE. The varying pressure level is indicated with a Ruben’s tube. (c) Soft energy harvester employing only soft materials, rubber, plastics and stretchable carbon black/oil composite conductors. Reprinted with permission.⁶⁵ Copyright 2011, American Institute of Physics.