In the last several decades, poly(vinylidene fluo-ride) (PVDF) and its copolymer with trifluoroethylene (P(VDF-TrFE)) have been studied extensively for their ferroelectric and electromechanical properties [1–4]. Re-cently, it was discovered that by proper defect modifi-cations, the normal ferroelectric P(VDF-TrFE) copoly-mer can be converted to a relaxor ferroelectric poly-mer, which is the first and only known ferroelectric polymer relaxor [5, 6]. Interestingly, the relaxor fer-roelectric polymers exhibit large electrostriction and high room temperature dielectric constant, which are attractive for a broad range of applications such as acoustic transducers, microactuators in MEMS, and electro-optic devices. These advances indicate the great potential of polymeric materials for achieving high func-tional responses compared with their inorganic counter-parts,aswellasthegreatneedtounderstandthemolecular origins of these responses.