Bioinspired Aquatic Propulsion Mechanisms with Real-Time Variable Apparent Stiffness Fins. - Shunichi Kobayashi; Tomomasa Ozaki; Masataka Nakabayashi; Hirohisa Morikawa; Akitoshi Itoh (ROBIO, 2006)

A novel propulsion mechanism using a fin with a variable-effective-length spring. - Masataka Nakabayashi; Reiji Kobayashi; Shunichi Kobayashi; Hirohisa Morikawa (ROBIO, 2008)