Performance characterization of a miniature spiral-channel viscous pump

This work describes the development and testing of a miniature spiral-channel viscous pump. The pump consists of a 12 mm diameter spiral disk on which a spiral-channel is machined with heights of 1 or 2 mm, a width of 1 mm and a spiral length (angular span) of 2.5π or 3.5π. The spiral-channel forms a fluid passage through which fluid is dragged due to the rotation of the spiral-channel under a stationary plate. Fluid inlet and outlet ports are located at the ends of the spiral-channel. Experimental flow rates and pressure rise data are obtained for rotational speeds from 1000 to 5000 rpm for pumping glycerin, where a maximum flow rate and pressure difference of 3.05 ml/min and 353 mbar is achieved at channel design parameters: ww/h = 1.0, and Δθ = 3π. The flow rate of the pump was found to increase nearly linearly with rotational speed and decrease linearly with the pressure head imposed on the pump. Advantages of spiral pump include simplicity in fabrication, ability to pump particle-laden fluids, and can operate with no valves.