Abstract: A planar microfluidic membraneless flow cell. The design eliminates the need for a mechanical membrane, such as a polyelectrolyte membrane (PEM) in a fuel cell, by providing a flow channel in which laminar flow regimes exist in two fluids flowing in mutual contact to form a “virtual interface” in the flow channel. In the flow cell, diffusion at the interface is the only mode of mass transport between the two fluids. In a fuel cell embodiment, a planar design provides to large contact areas between the two streams, which are fuel and oxidant streams, and between each stream and a respective electrode. In some embodiments, silicon microchannels, of fixed length and variable width and height, have been used to generate power using formic acid as fuel and oxygen as oxidant. Power densities on the order of 180 ?W/cm2 have been obtained using this planar design.

Abstract: The invention provides a process for treating a polyester fiber comprising the steps of providing a bicomponent fiber comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate) which has been heat-treated at a first temperature and cooled to lower than about 70° C. and has an initial crimp contraction value and a developed crimp contraction value, applying tension to the fiber of about 0.001 to 0.088 dN/tex, heat-treating the fiber at a second heat-treating temperature no lower than about 75° C. and no higher than the first heat-treating temperature, cooling the fiber to lower than the second heat-treating temperature, and releasing the tension from the fiber to give a fiber having a reduced crimp contraction value. The invention also provides a bicomponent fiber comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate) having a reduced crimp contraction value of about 6% to 15%.

Abstract: The invention provides a process for treating a polyester fiber comprising the steps of providing a bicomponent fiber comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate) which has been heat-treated at a first temperature and cooled to lower than about 70° C. and has an initial crimp contraction value and a developed crimp contraction value, applying tension to the fiber of about 0.001 to 0.088 dN/tex, heat-treating the fiber at a second heat-treating temperature no lower than about 75° C. and no higher than the first heat-treating temperature, cooling the fiber to lower than the second heat-treating temperature, and releasing the tension from the fiber to give a fiber having a reduced crimp contraction value. The invention also provides a bicomponent fiber comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate) having a reduced crimp contraction value of about 6% to 15%.