An Integrated Centrifugal Degassed PDMS-Based Microfluidic Device for Serial Dilution

Abstract

We propose an integrated serial dilution generator utilizing centrifugal force with a degassed polydimethylsiloxane (PDMS) microfluidic device. Using gas-soluble PDMS as a centrifugal microfluidic device material, the sample can be dragged in any arbitrary direction using vacuum-driven force, as opposed to in a single direction, without adding further actuation components. The vacuum-driven force allows the device to avoid the formation of air bubbles and exhibit high tolerance in the surface condition. The device was then used for sample metering and sample transferring. In addition, centrifugal force was used for sample loading and sample mixing. In this study, a series of ten-fold serial dilutions ranging from 100 to 10−4 with about 8 μL in each chamber was achieved, while the serial dilution ratio and chamber volume could easily be altered by changing the geometrical designs of the device. As a proof of concept of our hybrid approach with the centrifugal and vacuum-driven forces, ten-fold serial dilutions of a cDNA (complementary DNA) sample were prepared using the device. Then, the diluted samples were collected by fine needles and subject to a quantitative polymerase chain reaction (qPCR), and the results were found to be in good agreement with those for samples prepared by manual pipetting.

Integrated membranes within centrifugal microfluidic devices: a review

“…Likewise, microdevices that make use of the pre-existing substrate, either as microfluidic paper or cloth-based analytical devices (μPADs or μCADs) or composed solely of poly(dimethyl sulfoxide) (PDMS), [65][66][67] for functioning as a membrane will not be included. 61,68 Finally, biological membranes (derived in vivo) will also be excluded from this discussion due to their markedly unique integration strategies and usages. [69][70][71] However, this exclusion does not extend to synthetically processed membranes (derived in vitro) that have been additionally functionalized with biological material, or are classified as "biomimetic", nor to the biopolymer cellulose derivatives.…”

Novel Pumping Methods for Microfluidic Devices: A Comprehensive Review

“…The following device is a combination of two types of flow-driven methods [ 93 ]. The authors used centrifugal force combined with vacuum-driven force to drag the sample through the PDMS microfluidic chip.…”

Recent Advances in Multifunctional Microneedle Patches for Wound Healing and Health Monitoring

“…[ 77 ] Comparatively speaking, PTFE molds have better permeability. [ 78 ] PDMS mold is placed in a vacuum environment to remove bubbles, [ 79 ] while PTFE mold can draw a viscous aqueous polymer solution into the pores to facilitate casting. It is noteworthy that a minor amount of residual air remaining in the MP molding holes can lead to poor filling accuracy of raw materials and the integrity of the MP shapes.…”