Additive Manufacturing of Liquid Metal Emulsions, Polymer Composites and Synthetic Fascia for Soft, Stiff and Tough Multifunctional Materials

Materials of the future require burgeoning combinations of outstanding properties (e.g.’s, mechanical, electrical, and stimuli-responsive), which can only be realized through the careful design of new feedstocks, digital designs, and additive manufacturing. My talk will cover two broad examples of current and ongoing work from our group towards this effort. The first example will cover our work on designing liquid metal emulsions for 3D printed soft conductors and new types of soft power sources. For the former, we will present liquid metal emulsions that are compatible with direct ink writing (DIW) and can be combined with multi-material printing and automated pick-and-place to realize integrated soft and stretchable electronic devices and wearable haptics displays. For the latter we will present new liquid metal emulsions that can be molded into soft packaging to form soft galvanic cells that for stretchable power sources and self-powered keypads. The second example will highlight our work on developing new heterogeneous multiscale epoxy composites and synthetic fascia for high stiffness and high toughness 4D printed electrically controllable multifunctional structures that detect and tolerate damage. We employ these materials to print designs in a flat configuration that change shape into a lifting robot. The actuators formed by these materials exhibit maximum actuation stresses and specific forces that are larger than any other 3D printed actuators to date, with self-sensing and closed loop control capabilities. Our synthetic fascia toughening approach allows these actuators to detect damage and retain a significant amount of their performance even after the actuators are fractured. By printing these materials into various lattice designs we demonstrate flat configurations that change shape into various 3D surfaces with a range of mean and double curvatures. Finally, we combine these materials to create a 3D lattice-based quadruped robot that can crawl, and a 3D sensing hemispherical cap that can detect and tolerate being run over by a car.