Structuring the reduced graphene oxide/polyHIPE foam for piezoresistive sensing via emulsion-templated polymerization

•Piezoresistive foams are prepared by using emulsion template method.•Pore structure of the foam was regulated by pH and GO loading in the emulsion.•Foams with unimodal and broad pore size distribution, and hierarchically porous structure were realized.•Porous hierarchy can improve load transfer efficiency, thus enhancing sensing performance.•Hierarchically structured foams have higher sensitivity and broader responsive range.