A device including an enclosure that encapsulates a plurality of particles dispersed in a matrix material. The particles are formed of a material having substantial bulk thermal conductivity of at least about one watt per meter-Kelvin (1 W/[mK]) at a standardized measurement temperature of about 68° F. In the device, the enclosure is configured upon deformation to allow a portion of the matrix material to escape while retaining at least a portion of the particles within the enclosure. A system that includes an enclosure that encapsulates a plurality of such particles dispersed in a matrix material, the enclosure being located between first and second objects. In the system, the enclosure has through-pores communicating between an interior of the enclosure and an exterior of the enclosure, and at least a portion of the particles have diameters that are larger than a maximum diameter of the through-pores.