Centrifugal microfluidics for biomedical applications

Abstract

The development of a rapid, miniaturized, and efficient on-chip sample preparation for "real" sample analysis remains a major bottleneck for the realization of a lab-on-a-chip approach in point-of-care diagnostics. We developed a fully integrated and automated labon-a-disc using centrifugal microfluidics to provide a "sample-in and answer-out" type of biochemical analysis solution with simple, size-reduced, and cost-efficient instrumentation.1 Here, I present various examples of the fully integrated "lab-on-a-disc" developed for broad applications ranging from medical diagnostics to food, environment, and energy applications (Fig. 1A). Active valves on a spinning discWe pioneered the concept of laser-irradiated ferrowax microvalves (LIFM) with colleagues at Samsung Advanced Institute of Technology (SAIT), which provided a simple and robust tool for obtaining fluidic control on a spinning disc.2 The key achievement of this work was the rapid and wireless actuation of multiple valves by simple laser irradiation on nanoheaters, which are 10-nm-sized ferro-oxide nanoparticles dispersed in paraffin wax (Fig. 1B).2 The response time of both the normally open and normally closed valves was very short, and the actuation of the valves was independent of the sequence of the spin speed, sample type, or material properties of the substrates. More recently, we

Phase-selective graphene oxide membranes for advanced microfluidic flow control

“…Kim et al 22 developed a flow switch by using a capillary valve upstream of an open chamber and unique threedimensional (3D) junction geometry. A similar router, solely 1 controlled by the rotationally actuated hydrodynamic Coriolis pseudo-force, was reported by Brenner et al 23 . This virtual routing concept was further refined by Haeberle et al, who successfully extracted DNA from calf thymus using silica beads by alternating the sense of rotation 24 .…”

“…The thickness of the GO membrane was then measured using a 3D microscope (Keyence, VHX-5000 series, Digital Microscope, Itasca, IL, USA). For this experiment, a 100% DI water solution was used, and the burst frequency required for flow was once again recorded and converted to burst pressure using Equation (1). As seen in Figure 6, the burst pressure increases with increasing thickness of the membrane.…”

“…Centrifugal microfluidics offers the benefit that the force field can be accurately controlled over several orders of magnitude by a spindle motor 1 . Such 'Lab-on-aDisc' (LoaD) platforms have emerged as a highly useful tool in biomedical diagnostics because many of the necessary laboratory unit operations (LUOs) in bioanalysis, such as pumping 2 , plasma extraction 3 , mixing 4 , and metering 5 , can be fully automated and implemented.…”

“…Such 'Lab-on-aDisc' (LoaD) platforms have emerged as a highly useful tool in biomedical diagnostics because many of the necessary laboratory unit operations (LUOs) in bioanalysis, such as pumping 2 , plasma extraction 3 , mixing 4 , and metering 5 , can be fully automated and implemented. Liquid-handling steps can then be controlled by running a designated spin-frequency protocol to modulate interactions between on-disc liquids and microstructures 1 . The disc cartridge can also be designed to store all required reagents and then safely encapsulate potentially biohazardous samples 6 .…”

Rapid, Low-Cost Prototyping of Centrifugal Microfluidic Devices for Effective Implementation of Various Microfluidic Components

“…The primary forces enabling fluidic operations to be achieved are the centrifugal, Coriolis, and capillary forces. A number of detailed reviews of centrifugal microfluidic systems provide theoretical descriptions of the forces and their applications [3][4][5], and thus only a brief summary with example applications of each force is provided below.…”