Composite material used as a strain gauge

In one general aspect, an apparatus comprises a material including a non-layered mixture of an polymeric foam with a plurality of voids; and a plurality of conductive fillers disposed in the polymeric foam. The apparatus may produce an electrical response to deformation and, thus, function as a strain gauge. The electrical response may be a decrease in electrical resistance. The electrical response may be an electric potential generated. The conductive fillers may include conductive nanoparticles and/or conductive stabilizers. In another general aspect, a method of measuring compression strain includes detecting, along a first axis, an electrical response generated in response to an impact to a uniform composite material that includes conductive fillers and voids disposed throughout an elastomeric polymer, and determining a deformation of the impact based on the electrical response. The impact may be along a second axis different from the first axis.