See this wiki page: http://en.wikipedia.org/wiki/Electroactive_polymers

IPMCs work on the principle of displacement of ions..  and they normally require a solvent in which to actuate.. but some IPMCs can also actuate in air, but the degree and extent of actuation is pretty low.

 EAPs work on many principles.. dielectric (mostly elastomers but require very high applied voltages to the tune of hundreds of volts), piezo-electric (PVDF), visible light induced actaution like in azobenzene based polymers, Infra-red induced actuators like CNT or Graphene, heat or magnetic induced actuators..

Ionic polymer–metal composites is one of many kind of electroactive polymers .            for example , ionic polymer gel is electroactive polymer and it also use in soft robots ,and Conducting polymers is also an electroactive polymer and use in soft robots ,but each one of these polymers has a special properties led to use in special application 

so.. all these polymers we can called them "electroactive polymers " 

Electroactive polymers (EAPs) are relatively a new and remarkable class of materials which can be used both as sensors and actuators (Bar-Cohen 2001). Conductive polymers (CP), and ionic metal polymer composites (IPMC) are categorized as electroactive polymeric materials which exhibit interesting sensing and actuating behaviors (Smela 2003). They are among the best candidates for use in solar cells, sensors, and actuators (Otero and Teresa 2001, Wallace et al. 2003). Due to their (i) large strains of up to 39%, (ii) bio-compatibility, (iii) micro- and nano-scale manufacturing feasibility

and, (iv) relatively low actuation voltages (Madden et al. 2004, Jager et al. 2000, Smela 2003, Shahinpoor et al. 2007, Hara et al 2005, Carpi and Smela 2009) EAPs are candidate materials for the state of the art applications in an array of devices ranging from biomedical appliances through artificial organs to micro-electro-mechanical systems (MEMS).

it is clear that the reaction of polymers with metals have different line where to go and what we want to do.