Composable Behavioral Models and Schematic-Based Simulation of Electrokinetic Lab-on-a-Chip Systems

Abstract

This paper presents composable behavioral models and a schematic-based simulation methodology to enable topdown design of electrokinetic (EK) lab-on-a-chip (LoC). Complex EK LoCs are shown to be decomposable into a system of elements with simple geometry and specific function. Parameterized and analytical models are developed to describe the electric and biofluidic behavior within each element. Electric and biofluidic pins at element terminals support the communication between adjacent elements in a simulation schematic. An analog hardware description language implementation of the models is used to simulate LoC subsystems for micromixing and electrophoretic separation. Both direct current (dc) and transient analysis can be performed to capture the influence of system topology, element sizes, material properties, and operational parameters on LoC system performance. Accuracy (relative error generally less than 5%) and speedup (> 100×) of the schematic-based simulation methodology are demonstrated by comparison to experimental measurements and continuum numerical simulation. Index Terms-Behavioral model, dispersion, lab-on-a-chip, micromixing, schematic-based simulation, top-down design. NOMENCLATURE Variables A Maximum concentration of species band. c Concentration of species band. c m Channel width-averaged concentration of species band. c p pth moment of the concentration in a longitudinal filament of the species band. C e Electric conductivity of buffer, S/m. d n Mixing concentration coefficients. d m Mixing concentration coefficients at inlet of converging/diverging mixing intersection. D Molecular diffusivity of species, m 2 /s. E Electric field strength, V/cm. h Depth of microchannels, µm. I Electric current through buffer, A. L Length of microchannels, µm. L det Detector path length, µm.

Systematic modeling of microfluidic concentration gradient generators

“…Compared to previous studies, our effort exhibits three significant novelties. First, in contrast to the previous work focusing on electrokinetic flow [20,21], this paper extends the element models to accommodate pressure-driven flow. Second, while resistor-based models [12,14], which exploit the analogy between electric circuitry and fluidsample transport, impose the complete mixing constraint on device design, our approach allows concentration profiles (rather than a single average concentration value) to propagate within the entire network.…”

Macro-micro modeling design in system-level and experiment for a micromixer

“…Jeon et al 16 researched the periodic and composite waveform of species concentration. Wang et al 17 presented novel microfluidic networks to generate complex concentration profiles along the channel width by integrating linear and bell-shape created by T shape or cross-shape mixers, and a design approach for their proposed device based on iterative evaluation of the behavioral model.…”

Digital Microfluidic Biochips: A Vision for Functional Diversity and More than Moore

“…Traditional (continuous-flow) microfluidic technologies are based on the continuous flow of liquid through microfabricated channels [5,[7][8]. Continuous-flow systems are inherently difficult to integrate because the parameters that govern flow field (e.g.…”