Prof. Tao XIE's Group

    3D printing has witnessed a new era in which highly complexed customized products become reality. Realizing its ultimate potential requires simultaneous attainment of both printing speed and product versatility. Amongst various printing techniques, digital light processing (DLP) stands out in its high speed but is limited to intractable light curable thermosets. Thermoplastic polymers, despite their reprocessibility that allows more options for further manipulation, are restricted to intrinsically slow printing methods such as fused deposition modeling. Extending DLP to thermoplastics is highly desirable, but is challenging due to the need to reach rapid liquid solid separation during the printing process. Here, we report our successful attempt for DLP printing of thermoplastic polymers, realized by controlling two competing kinetic processes (polymerization and polymer dissolution) simultaneously occurred during printing. With a selected monomer 4-acryloylmorpholine (ACMO), we demonstrate printing of thermoplastic 3D scaffolds that can be further converted into various materials/devices utilizing its unique water-soluble characteristic. The ultralow viscosity of ACMO, along with surface oxygen inhibition, allows rapid liquid flow toward high speed open air printing. The process simplicity, enabling mechanism, and material versatility broaden the scope of 3D printing in constructing functional 3D devices including reconfigurable antenna, shape-shifting structures, and microfluidics. The first author is Doctor candidate Shihong Deng.

Online reading: https://onlinelibrary.wiley.com/doi/10.1002/adma.201903970