{'fraction_non_alphanumeric': 0.023588277340957826, 'fraction_numerical': 0.0, 'mean_word_length': 5.422018348623853, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Microfluidics based on-demand generation of non-woven and single polymer microfibers.

In this work, we present a microfluidics based microfiber fabrication method with ability to control both the fiber size as well as the extent of coiling of the generated fiber. This latter feature allows on-demand generation of both non-woven and single fiber within the same device, broadening the scope of application of the fabricated fibers. Using a hybrid Polydimethylsiloxane (PDMS)-Glass microfluidic device, we implement a coflowing solvent removal technique to generate Polyethylene oxide (PEO) fibers. Characterization of fibers through Fourier Transform Infrared (FTIR) spectroscopy and Differential Scanning Calorimetry (DSC) confirm the production of solvent-free, pure PEO fibers. Control over fiber size using both inner and outer liquid flow rates is demonstrated through Scanning Electron Microcopy (SEM) imaging. More crucially, we employ a complementary flow towards the downstream end of the fiber solidification region to control the extent of coiling of the generated fiber. By simple variation of the complementary flow, we induce a transition from a non-woven fiber to a single fiber. The presented technique is expected to broaden the scope of microfluidics as a tool for continuous generation of microfibers with wider range of applications, than the existing microfluidics techniques.