Polymeric Composites With Tunable Properties

A variety of polymeric composites with tunable mechanical stiffness and electrical conductivity are claimed herein. For example, the composite may have an elastomeric matrix, a plurality of tunable particles, and a plurality of conductive fibers embedded in the matrix. The composites may also be a tunable foam matrix and an elastomeric matrix. In some embodiments, the composites are a low melting point alloy (LMPA) foam infiltrated by an elastomer, whose stiffness can be tuned by more than two orders of magnitude through external heating. In other embodiments, the composite may be a conductive particle-fiber-matrix three-component composite capable of changing its elastic rigidity rapidly and reversibly when powered with electrical current.