An apparatus for measuring rheological properties of Newtonian and non-Newtonian fluids, comprising: - at least one micro-rheometer comprising a microchannel with an inlet, an outlet, and a sensor array arranged along the microchannel to measure rheological properties of a fluid flowing through the microchannel; wherein the sensor array comprises a plurality of pairs of electrodes (8, 8') with a known physical disposition along the microchannel, the two electrodes of each pair of electrodes being placed face to face within the microchannel to function as an electronic switch when the fluid flows through them; and - a data acquisition system in connection with the sensor array, comprising an electronic circuit connected to the pairs of electrodes (8, 8') and configured for: detecting the timing of the electronic switching, in the electronic circuit, of the pairs of electrodes (8, 8') as the fluid passes by, obtaining, from the timing of the electronic switching and the physical disposition of the pairs of electrodes (8, 8'), the flow velocity of the fluid inside the microchannel, and obtaining the rheological properties of the fluid using the acquired flow velocity of the fluid, the dimensions of the micro-rheometer and the pressure at which the fluid is injected in the micro-rheometer; characterized in that in the electronic circuit of the data acquisition system each pair of electrodes (8, 8') is connected to an amplifier electronic circuit to ensure an ultra-low electrical current flow (I E) through the short-circuit created by the fluid and the pair of electrodes (8, 8') to avoid damaging the fluid. - at least one micro-rheometer comprising a microchannel with an inlet, an outlet, and a sensor array arranged along the microchannel to measure rheological properties of a fluid flowing through the microchannel; wherein the sensor array comprises a plurality of pairs of electrodes (8, 8') with a known physical disposition along the microchannel, the two electrodes of each pair of electrodes being placed face to face within the microchannel to function as an electronic switch when the fluid flows through them; and - a data acquisition system in connection with the sensor array, comprising an electronic circuit connected to the pairs of electrodes (8, 8') and configured for: detecting the timing of the electronic switching, in the electronic circuit, of the pairs of electrodes (8, 8') as the fluid passes by, obtaining, from the timing of the electronic switching and the physical disposition of the pairs of electrodes (8, 8'), the flow velocity of the fluid inside the microchannel, and obtaining the rheological properties of the fluid using the acquired flow velocity of the fluid, the dimensions of the micro-rheometer and the pressure at which the fluid is injected in the micro-rheometer; characterized in that in the electronic circuit of the data acquisition system each pair of electrodes (8, 8') is connected to an amplifier electronic circuit to ensure an ultra-low electrical current flow (I E) through the short-circuit created by the fluid and the pair of electrodes (8, 8') to avoid damaging the fluid. detecting the timing of the electronic switching, in the electronic circuit, of the pairs of electrodes (8, 8') as the fluid passes by, obtaining, from the timing of the electronic switching and the physical disposition of the pairs of electrodes (8, 8'), the flow velocity of the fluid inside the microchannel, and obtaining the rheological properties of the fluid using the acquired flow velocity of the fluid, the dimensions of the micro-rheometer and the pressure at which the fluid is injected in the micro-rheometer;