Electrokinetic flow meter

A new concept of a micro flow meter is developed for measuring the flow rates of buffer solutions. The liquid flow rate through a glass rectangular micro channel is obtained by measuring electric signals generated electrokinetically. A model is presented which allows for flow rate measurements independent of the cation concentration. Experimental investigations are performed in order to demonstrate the proposed concept. The proposed flow meter is able to measure the flow rate of phosphate buffered saline solutions at various cation concentrations, with less than 10% error. The electrokinetic flow meter has a linear range that is several orders of magnitude wider than conventional thermal flow meters. This flow meter may be used to monitor and control the liquid flow in microfluidic systems.