Due to high surface-to-volume ratio of nanoscale structures, surface stress effects have a significant influence on their behavior. In this paper, a two-dimensional problem for an elastic layer that is bonded to a rigid substrate and subjected to an inclined concentrated line load acting on the surface of the layer is investigated based on Gurtin-Murdoch continuum model to consider surface stre...

This paper demonstrates a methodology for micromixing that is sufficiently simple that it can be used in portable microfluidic devices. It illustrates the use of the micromixer by incorporating it into an elementary, portable microfluidic system that includes sample introduction, sample filtration, and valving. This system has the following characteristics: (i) it is powered with a single hand-...

analytical chemistry has experienced, as well as other areas of science, a big change due to the needs and opportunities provided by analytical nanoscience and nanotechnology. now, nanotechnology is increasingly proving to be a powerful ally of analytical chemistry to achieve its objectives, and to simplify analytical processes. moreover, the information needs arising from the growing nanotechn...

This article presents a multichannel droplet-based surface plasmon resonance platform. The platform comprises a digital electrowetting-on-dielectric (EWOD) microfluidic device coupled to surface plasmon resonance imaging (SPRi). SPRi is now a well-established detection technique that enables in-situ monitoring of multiple reactions occurring at the surface of the chip without the use of labels....

A microfluidic device denoted the Phase Chip has been designed to measure and manipulate the phase diagram of multicomponent fluid mixtures. The Phase Chip exploits the permeation of water through poly(dimethylsiloxane) (PDMS) in order to controllably vary the concentration of solutes in aqueous nanoliter volume microdrops stored in wells. The permeation of water in the Phase Chip is modeled us...

A novel microfluidic system has been developed that uses the phenomenon of passive pumping along with a user controlled droplet based fluid delivery system. Passive pumping is the phenomenon by which surface tension induced pressure differences drive fluid movement in closed channels. The automated fluid delivery system consists of a set of voltage controlled valves with micro-nozzles connected...

A microfluidic device with integrated surface plasmon resonance (SPR) chemical and biological sensors based on arrays of nanoholes in gold films is demonstrated. Widespread use of SPR for surface analysis in laboratories has not translated to microfluidic analytical chip platforms, in part due to challenges associated with scaling down the optics and the surface area required for common reflect...

Immobilization of cells inside microfluidic devices is a promising approach for enabling studies related to drug screening and cell biology. Despite extensive studies in using grooved substrates for immobilizing cells inside channels, a systematic study of the effects of various parameters that influence cell docking and retention within grooved substrates has not been performed. We demonstrate...

Microfluidic sensing platforms facilitate parallel, low sample volume detection using various optical signal transduction mechanisms. Herein, we introduce a simple mixing microfluidic device, enabling serial dilution of introduced analyte solution that terminates in five discrete sensing elements. We demonstrate the utility of this device with on-chip fluorescence and surface-enhanced Raman sca...