Latchable microfluidic valve arrays based on shape memory polymer actuators.

We report arrays of latching microfluidic valves based on shape memory polymers (SMPs), and show their applications as reagent mixers and as peristaltic pumps. The valve design takes advantage of the SMP's multiple stable shapes and over a hundred-fold stiffness change with temperature to enable a) permanent zero-power latching in either open or closed positions (>15 h), as well as b) extended cyclic operation (>3000 cycles). The moving element in the valves consists of a tri-layer with a 50 μm thick central SMP layer, 25 μm thick patterned carbon-silicone (CB/PDMS) heaters underneath, and a 38 μm thick styrene ethylene butylene styrene (SEBS) impermeable film on top.

Integration of an optical CMOS sensor with a microfluidic channel allows a sensitive readout for biological assays in point-of-care tests.

In this manuscript, a microfluidic detection module, which allows a sensitive readout of biological assays in point-of-care (POC) tests, is presented. The proposed detection module consists of a microfluidic flow cell with an integrated Complementary Metal-Oxide-Semiconductor (CMOS)-based single photon counting optical sensor. Due to the integrated sensor-based readout, the detection module could be implemented as the core technology in stand-alone POC tests, for use in mobile or rural settings.

Zebrafish embryo development in a microfluidic flow-through system.

The zebrafish embryo is a small, cheap, whole-animal model which may replace rodents in some areas of research. Unfortunately, zebrafish embryos are commonly cultured in microtitre plates using cell-culture protocols with static buffer replacement. Such protocols are highly invasive, consume large quantities of reagents and do not readily permit high-quality imaging.

A pressure driven injection system for an ultra-flat chromatographic microchannel.

A pressure-actuated on-chip injection system has been developed that is compatible with shallow microchannels with a very large aspect ratio, i.e. 1 microm deep and up to 1000 microm wide.

On-chip hydrodynamic chromatography separation and detection of nanoparticles and biomolecules.

For the first time, on-chip planar hydrodynamic chromatography is combined with UV absorption detection. This technique is suitable for size characterization of synthetic polymers, biopolymers, and particles. Possible advantages of an on-chip hydrodynamic chromatography system over conventional techniques, such as size exclusion chromatography, and field-flow fractionation are fast analysis, high efficiency, reduced solvent consumption, and easy temperature control.

A chip system for size separation of macromolecules and particles by hydrodynamic chromatography.

For the first time, a miniaturized hydrodynamic chromatography chip system has been developed and tested on separation of fluorescent nanospheres and macromolecules. The device can be applied to size characterization of synthetic polymers, biopolymers, and particles, as an attractive alternative to the classical separation methods such as size exclusion chromatography or field-flow fractionation. The main advantages are fast analysis, high separation efficiency, negligible solvent consumption, and easy temperature control.