Research On Preparation And Properties Of Tube-based Fused Deposition Modeled Polymer Devices

Functional polymer devices,which can respond to external physical stimuli,such as force,light,and heat,are widely used in wearable sensors,self-powered devices,and soft robots,especially nanogenerators with multi-level microporous structures and programmable soft robots.The high performance of functional polymer devices depends on the material composition,individualized shapes,and specific microstructures.However,the conventional chemical and physical processing techniques for microstructures generally suffer from cumbersome procedures,long manufacturing cycles,and low precision,which seriously limit the large-scale application of functional polymer devices.Fused deposition modeling(FDM),a type of Additive manufacturing(AM)technology,enables the rapid fabrication of high-precision complex 3D structures with the advantages of high forming efficiency,short molding cycles,and low manufacturing costs,making it an ideal way to prepare high-performance functional polymer devices.However,limited by inherent molding process characteristics,it is difficult to form polymer devices directly through traditional FDM with liquid,powdery,granular,or thermosetting materials.To tackle these challenges,a novel strategy,tube-based FDM printing,is proposed for the additive manufacturing of polymers,realizing the rapid construction of multi-level microstructures of functional materials for high-performance devices.In addition,a programmable photoresponsive smart nanocomposite is designed and synthesized,and a near-infrared(NIR)light-driven soft robot with structural deformation potential is successfully fabricated by tube-based FDM printing.Herein,the process and mechanism of tube-based FDM printing in forming multi-material and multi-level microstructures for polymer devices are explored and studied.The main work and results are as follows:(1)A novel type of FDM printing is proposed using polymer tubes as carrier boats.Using polymer tubes as carrier boats of materials with different shapes and properties,FDM printing realizes the forming of liquid,powdery,granular,or thermosetting materials,breaking through the limitations of traditional FDM technology on the form and properties of printing materials,thereby broadening the range of printable materials.In addition,the polymer tubes are used as carriers of glue for FDM printing.The adhesion between the fuses can be enhanced by the glue,which can efficiently improve the bonding strength and thereby enhance the mechanical properties of the FDM printed product.(2)High-performance insoluble and infusible biomass based triboelectric nanogenerators(IBTENGs)with multi-level microporous structures are rapidly fabricated by tube-based FDM printing.By FDM printing using polymer tubes as carriers,the rapid formation of biomass materials and the rapid construction of multi-level microporous structures are achieved.Combined with the high specific surface area of the FDM printed products,an IBTENG for mechanical energy-electrical energy conversion is successfully fabricated.The mechanism by which the multi-level microporous structure affects the electromechanical conversion performance of the IBTENG has been explored.The fabricated IBTENG achieves effective harvesting and utilization of mechanical energy,with an energy conversion efficiency of 78%,which can be utilized to illuminate two seriesconnected LED bulbs(3 W),showing durability and stability in 200000 cycles.(3)A programmable NIR light-driven soft robot is fabricated using tube-based FDM printing.Based on the phase transition of liquid crystal elastomer(LCE)and high elastic phase change material(HEPCP),as well as the light absorption and photothermal conversion effects of multi-walled carbon nanotubes(MWCNTs),a NIR light-driven smart material LCE/HEPCP/MWCNTs(LHM)for additive manufacturing is designed and synthesized.The light-driven performance of the smart material LHM-based soft robots is studied,which can execute various tasks,including bending,walking forward and backward,twisting,spiral unwinding,and sit-ups.The additive manufacturing of smart material LHM is achieved through the proposed tube-based FDM printing method,and a light-driven soft robot with structural deformation potential is successfully fabricated.In this paper,the forming process,response performance,and working mechanism of functional polymer devices with multi-level microstructures printed with FDM are thoroughly investigated.A novel FDM printing technology using polymer tubes as carriers is proposed,which breaks through the limitations of traditional FDM technology on the morphology and properties of printing materials,enables the rapid forming of liquid,powdery,granular,and thermosetting polymer materials,and completes the rapid construction of multi-level microstructures.A feasible and reliable technical path is provided for the rapid construction of multi-level microporous structures of difficult-toprocess biomass materials.In addition,a NIR light-response smart material LHM is developed,and its application potential in the field of additive manufacturing through the proposed tube-based FDM method is explored,providing a promising path for the development of intelligent additive manufacturing technology.