Electrospinning is a highly promising technique to produce polymeric nanofibers. The technique is increasingly used in many different applications due to the high tailorability of the process and end products. Nano-diameter fibers tremendously increase the surface area to volume ratio which is very desirable in sensing and biomedical applications. This paper reports on formation of electrically conductive nanofibers for strain sensing purposes. Polymeric fibers that are mixed with graphene nanoparticles are electrospun to form conductive fiber mats. The fiber mats are converted into yarns. Later these yarns are characterized and calibrated to be used as strain sensing elements. Scanning Electron Microscopy was used to investigate the multifunctional composite nano-fibers. The effects of four main factors: voltage, solution concentration, flow rate, distance and interactions between these factors are investigated by design of experiment analysis.