Phase-selective graphene oxide membranes for advanced microfluidic flow control

Abstract

For the first time, we harness the unique phase-selectivity of chip-integrated graphene oxide (GO) membranes to significantly enhance flow control on centrifugal microfluidic platforms. In this paper, we present novel processes for the assembly of these GO membranes into polymeric microfluidic systems and demonstrate that multilayer GO membranes allow the passage of water while blocking pressurized air and organic solutions.

Design Optimization of Centrifugal Microfluidic "Lab-on-a-Disc" Systems towards Fluidic Larger-Scale Integration

“…To this end, the bioanalytical protocols are dissected into laboratory unit operations (LUOs), each of them controlled by normally closed valve. Centrifugally implemented LUOs have been covered extensively in the literature, e.g., for metering / aliquoting [45][46][47], mixing [48][49][50][51], incubation, purification / concentration / extraction [35,52], homogenisation [53,54], particle filtering [55][56][57][58][59] and droplet generation [60][61][62].…”

A review on application of graphene‐based microfluidics

“…Gaughran et al harnessed the unique phase‐selectivity of chip‐integrated GO membranes to significantly enhance flow control on centrifugal microfluidic platforms. The furthermore investigated various unique features of GO, notably its solvent selectivity and air impermeability . Figure shows their GO tab assembly and characterization.…”

“…(e) Microscope image of the GO tab edge showing uniform distribution of flakes and the acceptably clean cut from the knife cutter. (f) SEM image of the GO membrane showing a multilayer stacked structure …”

Graphene‐Based Biosensors: Going Simple

“…[37] This membranes have also been tested for molecular sieving which could be applied in the generation of breakthrough biosensing architectures. [38,39] Although analytical lab-on-a-chip applications capitalizing on graphene derivatives properties are not widely reported in the literature, one can find encouraging approaches facilitating electrochemical amplification mechanisms, multiplexed optical detection strategies and a novel crystallographic analysis, [40][41][42] which are an excellent example of how the thickness, conductivity and transparency offered by graphene derivatives represent a powerful tool for lab-on-a-chip development"…”

“…Firstly, single layers undergo a folding and wrinkling effect to prevent collapsing into multilayers. [38,39] Secondly, some graphene deposition techniques tend to promote an extreme degree of such a folding and wrinkling effect (e.g. drop casting and spin coating, which reduce surface coverage and increase the roughness, deteriorating electrical performance).…”