Temperature-sensitive hydrogels based on poly(vinyl methyl ether) (PVME) with ferroelectric or ferromagnetic properties were synthesized by high-energy irradiation. Barium titanate and poly(vinylidene fluoride) (PVDF) were used as ferroelectric filler and Ni as ferromagnetic filler. The filled PVME hydrogels were synthesized by electron beam or gamma-ray irradiation (of a suspension with 5-50 wt % of filler (with respect to polymer mass) in a 20 wt % aqueous PVME solution). Filling of the gel reduces the absolute swelling degree at low temperatures, but do not influence the phase-transition temperature of the gel. The particle distribution of the fillers inside the gel was visualized by field emission scanning electron microscopy. The fillers were incorporated in the PVME network and fixed because of their size (inorganic particles), as well as by chemical bonds (PVDF). The ferroelectric or ferromagnetic properties of the filled gels were proved. Measurements in a corresponding alternating field provide the hysteresis loop, for both the ferromagnetic and ferroelectric gel. (c) 2005 Wiley Periodicals, Inc.