Nanofibers with side-by-side morphologies are electrospun from polyacrylonitrile and polyurethane using a microfluidic device. Laminar flow of the two polymer solutions through the device results in nanometer-diameter curly nanofibers with bicomponent cross-sections. The polyurethane half of the nanofibers can be dissolved in tetrahydrofuran, leaving a "U"-shaped cross-section as seen in the Figure.