D. Ravichandran, K. Song
Arizona State University,
Keywords: 3D printing, additive manufacturing, layers
Summary:Intelligent devices have versatile functionality and many applications, e.g., targeted drug delivery for cancer cell treatment or deep ocean reach in soft robotics. Stimuli-responsive polymers, including intelligent materials or shape memory polymers (SMP), have attracted much attention in additive manufacturing due to their ability to produce complex structures in all shapes. This work demonstrated the one-step fabrication of composite multiphase smart materials using the newly developed multiphase direct ink writing (MDIW) 3D printing process. The SMPs were formulated using ether and ester-based thermoplastic polyurethane (TPU) mixed with polycaprolactone (PCL) and iron oxide nanoparticles (Fe2O3), respectively, providing the temperature and magnetic responsive properties. In addition, the MDIW mechanism produces alternative layers of the materials giving an isotropic responsive behavior of the as-fabricated structures to the external stimuli. The fabricated shape-memory structures also had a wide range of thermal actuation temperature (40 - 65°C), high strain, and shape recovery rate (up to 500%). Our additive manufacturing showed high potential in forming layered structures for broad sensors, actuators, and soft robotics applications.