RESUMO
The objective of this research is to design and optimise a mini/micro-channel based surface accumulator of Escherichia coli to be detected by acoustic wave biosensors. A computational research has been carried out using the state of the art software, CFD-ACE with water as bacteria bearing fluid. E. coli bacteria have been modelled as random discrete particles tracked by solving the Lagrangian equations. The design challenges are to achieve low shear force (pico-N), high concentration at accumulation and high enough Reynolds number to avoid bacteria swimming. A range of low Reynolds number (Re) from 28.2 to 58.3 has been considered along with the effects of particle-boundary interactions, gravity, Saffman lift and Magnus lift. About four orders of magnitude higher concentration at accumulation than the inlet concentration and lower shear force in the order of less than pico-N have been achieved in the optimised design with particles accumulating at a specific location under random particle-boundary interactions.
Assuntos
Técnicas Biossensoriais/instrumentação , Contagem de Colônia Microbiana/instrumentação , Escherichia coli/isolamento & purificação , Citometria de Fluxo/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Ultrafiltração/instrumentação , Microbiologia da Água , Acústica/instrumentação , Técnicas Biossensoriais/métodos , Contagem de Colônia Microbiana/métodos , Simulação por Computador , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Escherichia coli/fisiologia , Citometria de Fluxo/métodos , Técnicas Analíticas Microfluídicas/métodos , Modelos Biológicos , Ultrafiltração/métodos , Movimentos da ÁguaRESUMO
The objective of this research is to design and optimize a mini/micro-channel based surface-accumulator of E. coli bacteria to be detected by acoustic wave biosensors. A computational approach has been carried out using the state of the art software, CFD-ACE with water as bacteria bearing fluid. E. coli bacteria have been modeled as random discrete particles tracked by solving the Lagrangian equations. The design challenges are to achieve low shear force (pico-N), high concentration at accumulation, and high enough Reynolds number to avoid bacteria swimming. A range of low Reynolds number (Re) has been considered along with the effects of particle boundary interactions, gravity, Saffman lift, etc. More than two orders of magnitude higher concentration at the accumulation than the inlet concentration, and lower shear force of less than pico-N have been achieved in the optimized designs.
