A new chiral material composed of a two-dimensional lattice of five-segment cranks, with the same handedness is experimentally and numerically studied. The sample, formed by a single layer of such structures, exhibits huge electromagnetic activity and a negative refraction index for linearly polarized waves. Both the chirality parameter and the bandwidth with the
negative refraction index are larger than those observed in chiral media composed of three-segment cranks. The material also shows pronounced electromagnetic activity (larger than 500 per wavelength). This observed behaviour is attributed to the fact that the five-segment configuration enhances the electromagnetic coupling compared with the three-segment configuration.
