Hand-powered vacuum-driven microfluidic gradient generator for high-throughput antimicrobial susceptibility testing

A 3D-printed microfluidic gradient generator with integrated photonic silicon sensors for rapid antimicrobial susceptibility testing

“…20 To answer these challenges and make AST procedures more appropriate for deployment at PoC, the integration of microfluidic gradient generators (GG) in AST systems is suggested. [7][8][9][10][11][12][30][31][32] These GG devices are designed to establish a desired antimicrobial dilution seriescombining advantages of automation, and minimized sample and reagents consumption. The automatically generated concentrations are then collected and used for BMD testing, or the AST procedure is performed within the microfluidic system.…”

“…Yet, tree-like gradient generators (based on a cascade of divisions and reunions with an additional branch at every level) that represent the standard system of such convective gradient generators are often constrained by a maximal flow rate (as thorough mixing is required between each reunion and division). 33 Moreover, reported convective GG AST systems only apply non-clinically relevant linear concentration gradients, 7,8,10 require inconvenient off-chip testing after antimicrobial solution collection, 8,11 need to be coupled with sophisticated microscopy analysis, 7,10 or provide AST results within ≥8 h 8,9 which in a clinical setting often corresponds to next-day results only. 13 See Table 1 for a summary of previously reported relevant convective GG devices for AST.…”

Microfluidics for antibiotic susceptibility testing

“…It is possible to use syringes to generate suction within an array of chambers, and this approach does not necessarily require PDMS-made devices to work. 76 Another instance of prefilling microfluidic chambers with antibiotics and later filling all the chambers with bacteria was shown in a hybrid PDMS-paper device, 77 where small pieces of paper with antibiotic were placed in chambers before the experiment. Such an approach is undoubtedly more convenient than spotting the antibiotics to chambers with a spotting machine, and although only 21 chambers were placed in the device, the system was used to for breakpoint analysis of bacteria from clinical samples.…”

Novel Pumping Methods for Microfluidic Devices: A Comprehensive Review

“…Zeng W. presented a hand-powered vacuum-driven device to rapidly generate different concentrations of the sample in microfluidic chambers. Syringes with a size of 1 mL were used as the vacuum source [ 92 ]. The platform was designed in the following way: two rows of dead-end culture chambers (C-chambers) connect with the main channel via both side channels (six on each side) and 12 vacuum chambers (V-chambers) located at the outer side of each C-chamber.…”