Microfluidic rectifier based on poly(dimethylsiloxane) membrane and its application to a micropump

Abstract

A microfluidic rectifier incorporating an obstructed microchannel and a PDMS membrane is proposed. During forward flow, the membrane deflects in the upward direction; thereby allowing the fluid to pass over the obstacle. Conversely, during reverse flow, the membrane seals against the obstacle, thereby closing the channel and preventing flow. It is shown that the proposed device can operate over a wide pressure range by increasing or decreasing the membrane thickness as required. A microfluidic pump is realized by integrating the rectifier with a simple stepper motor mechanism. The experimental results show that the pump can achieve a vertical left height of more than 2 m. Moreover, it is shown that a maximum flow rate of 6.3 ml/min can be obtained given a membrane thickness of 200 lm and a motor velocity of 80 rpm. In other words, the proposed microfluidic rectifier not only provides an effective means of preventing reverse flow but also permits the realization of a highly efficient microfluidic pump. V C 2013 AIP Publishing LLC.

A pneumatic valve controlled microdevice for bioanalysis

“…Herein we developed a different type of manually actuated pneumatic valves based on latching pneumatic valves. 25,32 The valves allow us to combine with the degassed polydimethylsiloxane (PDMS) dispensing method 10,[33][34][35] to build a microdevice for general serial assays. In the current work, manually actuated pneumatic valves were integrated in the microdevice, which circumvented the need for the expensive electromechanically operated valves or syringe pumps.…”

“…In the current work, manually actuated pneumatic valves were integrated in the microdevice, which circumvented the need for the expensive electromechanically operated valves or syringe pumps. 32 We combined the degassed PDMS pumping method 10,[33][34][35] with the manually actuated pneumatic valves to control the solution dispensing and mixing. To illustrate the application of the device, we used the microdevice to study the enzymatic kinetics of alkaline phosphatase.…”

Stimulus-active polymer actuators for next-generation microfluidic devices

“…In the latter case the cilia-like actuators have relatively large dimensions, 1 mm diameter and 8 mm length, but the fluid speeds measured reached correspondingly large values in the order of 19 mm/s. PDMS membranes with microscopic incisions have been reported for use as valves with flow-rectifying properties and the additional possibility to actively control the flow rate in the forward direction [95,96]: An elastic membrane with an incision is clamped between two rigid polymer plates and expands when pressure is applied in the forward direction, allowing fluid to pass. In the backward direction, expansion of the membrane is prevented, and thus fluid flow is blocked.…”

A Magnetic Micropump Based on Ferrofluidic Actuation

“…Many alterative actuation mechanisms have been proposed to achieve a pumping effect in microfluidic devices, including acoustic-wave-based, rotary, piezoelectric, thermopneumatic, electrostatic, electromagnetic and ferrofluidic methods [16][17][18][19][20][21]. Recently, Lee's group [22][23][24][25] developed an impedance-based micro pump based on electromagnetic actuation and including a copper microcoil, a glass microchannel, a glass cover plate and a PDMS diaphragm with a magnet mounted on its upper surface.…”