Biomedical Engineering Reference
In-Depth Information
electric field. They essentially treated the mechanism of collapse as a phase transition
phenomenon.
In the mid-1980s another pioneer, Danilo De Rossi, and coworkers out of
University of Pisa in Italy presented a series of papers on the determination of
mechanical parameters related to the kinetics of swelling of electroactive polymeric
gels. They were the first to discuss the analogs of biological tissues for mechano-
electrical transduction: tactile sensors and muscle-like actuators. Their contribution
has continued to the present time.
As early as the mid-1980s, another pioneer in this area from Japan, Yoshihito
Osada, and coworkers also presented possible theories of electrically activated mech-
anochemical devices using polyelectrolyte gels as well as mechanism and process
of chemomechanical contraction of polyelectrolyte gels under an electric field. Their
contributions have continued to the present time.
By the late 1980s and early 1990s new contributors to the mechanisms of
actuation and sensing of polyelectrolytes and ionic polymers had appeared. Shahin-
poor (1991, 1992) discussed conceptual design, kinematics, and dynamics of swim-
ming robotic structures using active polymer gels. He presented a set of ion transport
equations as well as continuity, conservation of momentum, and conservation of
energy equations involving the effect of an imposed electric field. Segalman et al.
(1991, 1992, 1993, 1994) presented a series of papers on modeling and numerical
simulation of electrically controlled polymeric muscles as active materials used in
adaptive structures and further presented a finite element simulation of the two-
dimensional collapse of a polyelectrolyte gel disk considering neo-Hookean consti-
tutive equations for the polymer network elasticity.
Shahinpoor (1993b) further presented a nonhomogeneous, large-deformation
theory of ionic polymeric gels in electric and pH fields. Attempts to formulate a
microelectromechanical theory for ionic polymeric gels as artificial muscles for
robotic applications were initiated in a series of papers by Shahinpoor (1993b, 1993c,
1993d, 1994a, 1994b, 1994c, 1994d, 1994e, 1994f, 1995d, 1995e, 1999b, 2000b,
2002e). Shahinpoor also presented a continuum electromechanics theory of ionic
polymeric gels as artificial muscles for robotic applications. Shahinpoor and Osada
(1995a) presented a theory on electrically induced dynamic contraction of ionic
polymeric gels based on electrocapillary and electro-osmotic forces.
Shahinpoor, Bar-Cohen, Simpson, et al. (1998) presented the first review paper
on IPMNCs as biomimetic sensors and robotic actuators and artificial muscles. de
Gennes and coworkers (2000) presented the first phenomenological theory for sens-
ing and actuation in ionic polymer-metal nanocomposites (IPMNCs). Asaka and
Oguro (2000) discussed the bending of polyelectrolyte membrane-platinum com-
posites by electric stimuli and presented a theory on actuation mechanisms in
IPMNCs by considering the electro-osmotic drag term in transport equations.
Nemat-Nasser and Li (2000) presented modeling on the electromechanical
response of IPMNCs based on the electrostatic attraction/repulsion forces in them.
Later, Nemat-Nasser (2002) presented a revised version of their earlier paper and
stressed the role of hydrated cation transport within the clusters and polymeric net-
works in IPMNCs. Nemat-Nasser and Wu (2003) have presented a discussion on the
role of backbone ionic polymer and, in particular, sulfonic versus carboxylic ionic
