Remotely tunable microfluidic platform driven by nanomaterial-mediated on-demand photothermal pumping

A novel on-demand photothermal microfluidic pumping platform is developed using the nanomaterial-mediated photothermal effect as the tunable microfluidic driving force.

Metachronal actuation of microscopic magnetic artificial cilia generates strong microfluidic pumping

Microscopic magnetic artificial cilia (μMAC) performing metachronal motion are experimentally demonstrated to generate unprecedented strong microfluidic flow.

Evaporation-Based Microfluidic Pump Using Super-Hydrophilic Diatom Biosilica Thin Films

Diatoms are a group of single-celled photosynthetic algae that use biochemical pathways to bio-mineralize and self-assemble three-dimensional photonic crystals with unique photonic and micro- & nano-fluidic properties. In recent years, diatom biosilica has been used in surface-enhanced Raman scattering (SERS) based optofluidic sensors for detection of a variety of chemical and biological molecules. In this paper, we present a study to develop a microfluidic pumping system using super-hydrophilic diatom thin films. The desire to develop such a system stems from the requirement to create a low-cost, self-powered microfluidic pumping system that can sustain a continuous flow over an extended period of time. The diatom biosilica acts not only as the driving force behind the flow, but also serves as ultra-sensitive SERS substrates that allows for trace detection of various molecules. Liquid is drawn from a reservoir to the tip of a 150μm inner diameter capillary tube positioned directly over the diatom film. A thin and long horizontal reservoir is used to prevent flooding on the diatom film when the liquid is initially drawn to the diatom film through a capillary tube from the reservoir. The connection of the meniscus from the capillary to the film was maintained from a horizontal reservoir for a recorded time of 20 hours and 32 minutes before the partially filled reservoir emptied. Flow rates of 0.38, 0.22 and 0.16μL/min were achieved for square biosilica thin films of 49mm2, 25mm2, and 9mm2 at a temperature of 63°F and 45% relative humidity respectively. A temperature-controlled system was introduced for the 49mm2 substrate and flow rates of 0.60, 0.82, 0.93, and 1.15μL/min were observed at 72, 77, 86, and 95°F at 21% relative humidity respectively. More testing and analysis will be performed to test the operation limits of the proposed self-powered microfluidic system.