A pneumatic valve controlled microdevice for bioanalysis

Abstract

This paper describes a pneumatic valve controlled microdevice for performing mixing and reaction. This microdevice combined the degassed polydimethylsiloxane (PDMS) pumping method with a syringe-actuated valve system to control the dispensing and mixing of nanoliter solutions. The syringe was used to manually generate vacuum and to open the valves. Upon the opening of the valve, the microchamber was filled with the solution, which was driven by the external atmosphere through the degassed PDMS microchannel. With this microdevice, the enzymatic kinetics of alkaline phosphatase converting the fluorescein diphosphate was studied, and the Michaelis-Menten kinetics was analyzed. The microdevice has the advantages of simplicity and low cost in fabrication and operation.

Microfluidic platform for the enzymatic pretreatment of human serum for the detection of the tuberculosis biomarker mannose-capped lipoarabinomannan

“…We chose to construct an externally controlled pneumatic microuidic device (ECPMD), a style of microuidic device which has been shown to be readily adapted to a wide range of uid mixing and metering processes. [29][30][31][32][33][34] Our ECPMD consists of three main components: (1) a uid-handling layer that contains the uid channels; (2) a control layer that consists of cavities for valves and chambers connected by tubing to the external pneumatic system and controller; and (3) a exible membrane that separates the uid-handling layer from the control layer and deforms in response to applied pneumatic inputs, opening and closing each of the valves and chambers in the uid-handling layer (Fig. S1 †).…”

Dynamical systems techniques for enhancing microfluidic mixing

“…Active methods are those which supply an energy to the system. These include for example pumping fluid back and forth (for example in the transverse direction to the channel flow in figure 1) using syringes or cross-channels [32,33,36,[50][51][52][53][54][55][56][57][58], vibrating boundary membranes to generate an additional interior flow velocity [52,53], or applying external oscillating electromagnetic fields to influence charged particles within the fluid [26,29,31,[59][60][61][62][63]. These methods will cause fluctuating velocities in the frame of reference of the flow barriers, thereby engendering transport across them.…”

Tunable Harmonic Flow Patterns in Microfluidic Systems through Simple Tube Oscillation

“…In comparison, active mechanisms take advantage of external stimuli to disturb flow. This includes a variety of mechanical, [30][31][32] pneumatic, [10,[33][34][35] thermal, [36] acoustic, [37,38] electrical, [39,40] and electrowetting [41,42] mechanisms to disturb the laminar flow. Despite these advances, their widespread application has been limited by their dependence on additional supporting equipment, which increases the overall size, cost, and complexity of the system, contradicting the principal promises of microfluidics for delivering small, inexpensive, and simple devices.…”