Systems, tools, and methods for enhancing a measurement of a fluid in a borehole, pipe, conduit and/or the like involve an electromagnetic measurement tool that includes a transmitting antenna configured to transmit electromagnetic energy, a receiving antenna configured to receive the electromagnetic energy, and a metamaterial element comprising a negative refractive index. The metamaterial element may focus the electromagnetic energy. The electromagnetic system may comprise one or more antennas that are disposed adjacent to or in contact with the fluid, electromagnetic energy may be transmitted via the transmitting antenna, and the electromagnetic energy may be received with the receiving antenna to measure a property of the fluid.