A Ghost-Valve micropumping paradigm for biomedical applications

Methods: A mathematical analysis based on the lubrication theory is given to govern this internal flow motions and to derive expressions of velocity stream function, pressure distributions, and net flow rate in a microchannel having two contracting sites.; Purpose: To present a novel micropumping “Ghost-Valve” principle that can be useful for many of biomedical applications. This pumping mechanism is inspired by microscale internal flow motions within insect tracheal networks, which is observed to be induced by localized rhythmic wall contractions.; Results: The derived flow velocity stream function suggests that, there exist contraction-induced stagnation planes “Ghost-Valves” in the neighbourhoods of channel collapsing sites. The dynamics (locations, birth/death) of these ghost valves have shown to be strong function of the assigned wall motion protocol, which can be tuned to control flow transport along the axial direction and produce unidirectional net flow.; Conclusions: An inelastic microchannel subjected to a zero pressure drop and undergoes localized rhythmic wall contractions can work as a micropump. The minimum requirement for this paradigm to produce a unidirectional net flow is; A channel with at least two contracting membranes that move with a distinct time-lag with respect each other. The presented ghost-valve pumping model is expected to function efficiently in the low Reynolds number flow regime. Therefore, it yields a potential usefulness in many of biomedical microdevices for drug delivery, point-of-care testing, and cardiac assistance devices. © 2015, Korean Society of Medical and Biological Engineering and Springer.