Versatile on-demand droplet generation for controlled encapsulation
| Autor: | Yooli Kim Light, Robert J. Meagher, Peng Liu, Anup K. Singh, Minsoung Rhee |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Fluid Flow and Transfer Processes
Analyte endocrine system Materials science Wheatstone bridge business.industry Multiphase flow Microfluidics Biomedical Engineering technology industry and agriculture Nanotechnology Lab-on-a-chip Condensed Matter Physics Chip complex mixtures eye diseases Volumetric flow rate law.invention Encapsulation (networking) Colloid and Surface Chemistry law Optoelectronics General Materials Science business Regular Articles |
| Popis: | We present a droplet-based microfluidic system for performing bioassays requiring controlled analyte encapsulation by employing highly flexible on-demand droplet generation. On-demand droplet generation and encapsulation are achieved pneumatically using a microdispensing pump connected to a constant pressure source. The system generates single droplets to the collection route only when the pump is actuated with a designated pressure level and produces two-phase parallel flow to the waste route during the stand-by state. We analyzed the effect of actuation pressure on the stability and size of droplets and optimized conditions for generation of stable droplets over a wide pressure range. By increasing the duration of pump actuation, we could either trigger a short train of identical size droplets or generate a single larger droplet. We also investigated the methodology to control droplet contents by fine-tuning flow rates or implementing a resistance bridge between the pump and main channels. We demonstrated the integrated chip for on-demand mixing between two aqueous phases in droplets and on-demand encapsulation of Escherichia coli cells. Our unique on-demand feature for selective encapsulation is particularly appropriate for bioassays with extremely dilute samples, such as pathogens in a clinical sample, since it can significantly reduce the number of empty droplets that impede droplet collection and subsequent data analysis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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