title: Lab-on-chip flow injection analysis system without an external pump and valves and integrated with an in line electrochemical detector.
abstract: Surface energy in small droplets can be used to drive samples through microchannels. When a sample fluid is spontaneously driven through a solution filled microchannel with liquid droplets on its entry (sample) and exit (reservoir) ports, it is termed as a passive pumping device. A passive pump driven microfluidic system integrated with microfabricated planar electrodes or electrode arrays (e.g., interdigitated electrode arrays or microband electrode arrays) can be considered as a manifold for flow injection analysis without an external pump and injector valve. Factors affecting the passive pump driven flow rate in a polydimethylsiloxane (PDMS)-glass hybrid microfluidic system, including the volume, viscosity, and surface tension of the sample solution and the tilt of the microfluidic channel, are analyzed. By placing 2 microL of hexacyanoferrate (II) solutions at the entry port of the device, peak shaped transients were recorded. The peak heights showed linear dependence on the sample concentrations between 3 x 10(-7) and 10(-5) M.
authors.affiliation: Biomedical Engineering Department, The University of Memphis, Memphis, Tennessee 38152, USA.
authors.forename: I-Jane
authors.initials: IJ
authors.lastname: Chen
authors.forename: Ernö
authors.initials: E
authors.lastname: Lindner
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D005295:Ferrocyanides / Q000032:analysis*; D017022:Flow Injection Analysis; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D013500:Surface Tension
chemical_list: D004129:Dimethylpolysiloxanes; D005295:Ferrocyanides; C116383:ferrocyn; C013830:baysilon