The electrical conductivity of blood is a crucial physiological parameter with diverse applications in medical diagnostics. Here, a novel approach utilizing a portable millifluidic nanogenerator lab-on-a-chip device for measuring blood conductivity at low frequencies, is introduced. The proposed device employs blood as a conductive substance within its built-in triboelectric nanogenerator system. The voltage generated by this blood-based nanogenerator device is analyzed to determine the electrical conductivity of the blood sample. The self-powering functionality of the device eliminates the need for complex embedded electronics and external electrodes. Experimental results using simulated body fluid and human blood plasma demonstrate the device's efficacy in detecting variations in conductivity related to changes in electrolyte concentrations. Furthermore, artificial intelligence models are used to analyze the generated voltage patterns and to estimate the blood electrical conductivity. The models exhibit high accuracy in predicting conductivity based solely on the device-generated voltage. The 3D-printed, disposable design of the device enhances portability and usability, providing a point-of-care solution for rapid blood conductivity assessment. A comparative analysis with traditional conductivity measurement methods highlights the advantages of the proposed device in terms of simplicity, portability, and adaptability for various applications beyond blood analysis.