Secure Air Traffic Control at the Hub of Multiplexing on the Centrifugo-Pneumatic Lab-on-a-Disc Platform

Abstract

Larger-scale integration (LSI) resides at the heart of comprehensive sample-to-answer automation and parallelisation of assay panels for frequent and ubiquitous bioanalytical testing in decentralised the point-of-use / point-of-care settings. With an emphasis on rotational, centrifugo-pneumatic flow control, this paper employs a virtual “digital twin” strategy, considering experimental tolerances, to efficiently design such “Lab-on-a-Disc” systems featuring high packing density, reliability, configurability, modularity, manufacturability, performance while minimizing development and fabrication cost.

Systematic Review of Centrifugal Valving Based on Digital Twin Modelling towards Highly Integrated Lab-on-a-Disc Systems

“…Several extensions of the rudimentary digital twin approach are proposed, e.g., inclusion of previously introduced flow control by event-triggering, rotational pulsing and delay modules, or further increase of real estate by vertical stacking of multiple fluidic layers. Valving performance can be improved by sophistication of valve layouts [94,95], e.g., with refined shapes, rounded contours, and anticounterfeit features [119], and migration from the hydrostatic model to computational fluidic dynamic (CFD) simulation. An advanced design tool could also include the bioassay kinetics.…”

“…After pointing out their numerous synergistical benefits, we designate a full section on siphon valves that run against the pneumatic counter pressure into an outlet chamber that is transiently sealed by a dissolvable-film (DF) membrane. Next, important performance metrics are defined which can guide the design optimization [94,95] towards fluidic LSI at high operational robustness before concluding with a comparison of passive valving techniques for LoaD platforms.…”

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

“…In prior publications, we have compared different rotationally actuated valving schemes for LoaD systems through a more general digital twin approach [76,82]. It turns out that normally-closed centrifugo-pneumatic (CP) siphon valves with a compression chamber of volume C that is initially sealed by dissolvable-film (DF) membrane offer many operational benefits; amongst them are wide tunability of the critical spin rate Ω (5), high operational robustness, and flexible configurability in real space as well as in the frequency domain.…”

“…The sample-to-answer automation of bioanalytical protocols representing comprehensively parallelized, multi-analyte assay panels including elements like calibrants, redundancies and dilution series, is enabled by fluidic larger-scale integration (LSI) in the backend [82]. Towards high packing densities, each valve design Γ hence needs to curtail their footprint in the radial, aerial and frequency domain, while concurrently meeting additional requirements, such as allowing a certain field strength (8) to assure proper execution of its upstream LUO.…”

“…The notion of microfluidic LSI has first elaborated in the early 2000s in the context of pneumatically controlled elastomeric systems [81]. Based on previous publications on 'digital twin' [80] modelling of fluidic performance and operational robustness on LoaD systems [76,82], valve retention frequencies and their band widths were identified as key performance indicators, and can directly be calculated, either algebraically of numerically, from the standard deviation of elementary input parameters, such as general (linear) machining and pipetting tolerances [83,84]. These statistical spreads can either be found in manuals or the literature, or be determined by lowcomplexity test structures; importantly, these basic parameters are broadly independent of the specific layout of a specific LoaD cartridge.…”