301
Nowadays, underwater surveillance, salvage, and military missions are research
areas for the use of unmanned undersea vehicles (UUVs). The principal difference
between underwater behaviour of these artifi cial constructs and fi sh is as follow:
“The maneuverability and control of UUVs during such operations is an obvious concern.
Typically, UUVs have rigid bodies, are driven using propellers, and produce their maneuvering forces with rigid control surfaces that are effective only when the fl ow of the water
past the UUV exceeds a minimum velocity.
In contrast, fi sh, which are remarkable in their ability to maneuver and to control their
body position, have, with few exceptions, fl exible bodies, and use fl exible fi ns that are
actively controlled to make the appropriate movement and assume the appropriate shape
for generating the forces required by a particular situation (e.g., maneuvers, hovering, highspeed stability, and braking),” (Tangorra et al. 2007b ).
Thus, to achieve success in the development of robotic constructs, principally we
need not only to be inspired by the form and shape of selected fi sh, but use the
corresponding biological or artifi cial materials for designing of robotic functional
segments like fi ns or tails. “Robotics engineers are able to combine the study and
the fi ndings of biology and engineering, while a group of researchers is actively
exploring the lightweight or micro-robotic fi sh with smart materials for actuation
and locomotion,” (Low 2009 ). In numerous studies, the robotic fi ns were constructed
to characterize specifi c features of the fi sh fi ns with respect to investigate “how the
fi ns’ kinematic patterns, their spatially varying mechanical properties, and the fl uid’s
rate of fl ow affected the magnitude and direction of each fi n’s propulsive forces,”
(Tangorra et al. 2011 ). Today, the design of smart materials to assist in studies on
stiffness and in the construction of robotic fi sh-like devices is the interesting
challenging task (Lauder et al. 2011 ), its realization is dependent on our knowledge
in biological materials of fi sh origin.
7.5.1 Fish and Designing of Smart Materials
Due to their higher energy conversion effi ciency and quieter operation compared to
traditional motors, special material actuators have been explored for propulsion.
Diverse smart material actuators include piezoelectric actuators, shape memory
alloy actuators, and electroactive polymer actuators (see for review Tan et al. 2006 ;
Aureli et al. 2010 ; Lauder et al. 2011 ). Ionic polymer-metal composites (IPMCs),
including ionic polymeric gel muscles (Shahinpoor 1992 ) are a particularly “promising
class of actuation materials for underwater robots, since they produce large bending
motions under low voltages (1–2 V), work well in water and other fl uids, and are
fl exible and biocompatible,” (Tan et al. 2006 ; see also Kim et al. 2005 ). The electrical
potential can determine geometry of electroactive polymer actuators. Elasticity,
damage tolerance and large actuation strains make them functionally similar to
biological muscles (Bar-Cohen 2001 ).
Tangorra and co-authors (2007) reported about development of “conducting
polymer actuators based on polypyrrole are for use in biorobotic fi ns that are
7.5 Robotic Fish-Like Devices
Nowadays, underwater surveillance, salvage, and military missions are research
areas for the use of unmanned undersea vehicles (UUVs). The principal difference
between underwater behaviour of these artifi cial constructs and fi sh is as follow:
“The maneuverability and control of UUVs during such operations is an obvious concern.
Typically, UUVs have rigid bodies, are driven using propellers, and produce their maneuvering forces with rigid control surfaces that are effective only when the fl ow of the water
past the UUV exceeds a minimum velocity.
In contrast, fi sh, which are remarkable in their ability to maneuver and to control their
body position, have, with few exceptions, fl exible bodies, and use fl exible fi ns that are
actively controlled to make the appropriate movement and assume the appropriate shape
for generating the forces required by a particular situation (e.g., maneuvers, hovering, highspeed stability, and braking),” (Tangorra et al. 2007b ).
Thus, to achieve success in the development of robotic constructs, principally we
need not only to be inspired by the form and shape of selected fi sh, but use the
corresponding biological or artifi cial materials for designing of robotic functional
segments like fi ns or tails. “Robotics engineers are able to combine the study and
the fi ndings of biology and engineering, while a group of researchers is actively
exploring the lightweight or micro-robotic fi sh with smart materials for actuation
and locomotion,” (Low 2009 ). In numerous studies, the robotic fi ns were constructed
to characterize specifi c features of the fi sh fi ns with respect to investigate “how the
fi ns’ kinematic patterns, their spatially varying mechanical properties, and the fl uid’s
rate of fl ow affected the magnitude and direction of each fi n’s propulsive forces,”
(Tangorra et al. 2011 ). Today, the design of smart materials to assist in studies on
stiffness and in the construction of robotic fi sh-like devices is the interesting
challenging task (Lauder et al. 2011 ), its realization is dependent on our knowledge
in biological materials of fi sh origin.
7.5.1 Fish and Designing of Smart Materials
Due to their higher energy conversion effi ciency and quieter operation compared to
traditional motors, special material actuators have been explored for propulsion.
Diverse smart material actuators include piezoelectric actuators, shape memory
alloy actuators, and electroactive polymer actuators (see for review Tan et al. 2006 ;
Aureli et al. 2010 ; Lauder et al. 2011 ). Ionic polymer-metal composites (IPMCs),
including ionic polymeric gel muscles (Shahinpoor 1992 ) are a particularly “promising
class of actuation materials for underwater robots, since they produce large bending
motions under low voltages (1–2 V), work well in water and other fl uids, and are
fl exible and biocompatible,” (Tan et al. 2006 ; see also Kim et al. 2005 ). The electrical
potential can determine geometry of electroactive polymer actuators. Elasticity,
damage tolerance and large actuation strains make them functionally similar to
biological muscles (Bar-Cohen 2001 ).
Tangorra and co-authors (2007) reported about development of “conducting
polymer actuators based on polypyrrole are for use in biorobotic fi ns that are
7.5 Robotic Fish-Like Devices