Lag-after-pulsed-separation microfluidic flowmeter for biomacromolecular solutions

A novel microfluidic flowmeter, the lag-after-pulsed-separation (LAPS) meter, has been developed to measure the flow rate of suspensions laden with protein or other charged macromolecules or particles. The LAPS meter operates on the time-of-flight principle previously employed for thermal flow meters. An upstream event (electrophoretic concentration of the particles in one section of the device) is detected downstream (by change in AC resistance). The time lag between the event and the detection is inversely proportional to the velocity, providing a non-invasive, no-moving-parts flow measurement. (C) 2003 Elsevier B.V. All rights reserved.