Session: 04-23-01: Functional Soft Composites - Design, Mechanics, and Manufacturing

Paper Number: 146345

146345 - Additive Manufacturing of Liquid Metal Elastomer Foams 

Elastomer composites with embedded liquid metal (LM) fillers are an emerging material architecture for creating highly functional materials that are soft, elastically deformable, and exhibit unique combinations of electrical, thermal, and mechanical properties. These materials are created from an emulsion system that is typically manufactured in bulk using replica molding or soft lithography techniques that results in primarily spherical inclusions with little control of shape, orientation, or spatial placement. Recently, we introduced a new direct ink writing 3D printing technique to program the LM microstructures (i.e., shape, orientation, and connectivity) on demand throughout a printed part. In contrast to inks with rigid particles that have fixed shape and size, emulsion inks with liquid phase fillers offer new opportunities to generate unique LM microstructures that are locked in during printing by controlling the print processing parameters. The processing parameters are specifically important because they directly impact the geometry of the printed filament, thereby influencing the quality and properties of the end product. Here, we introduce a new 3D printing strategy by harnessing the instability and fracture of viscoelastic inks to control the porosity throughout a printed part without the need of foaming agents or sacrificial templates. We construct a quantitative design guide for the selection of printing parameters with experimental validations. This new 3D printing strategy provides new ways of controlling the mechanical properties of elastomer composites. These capabilities are demonstrated by creating a bilayer capacitive sensor with a large dynamic range. The combination of the solid–liquid composites with our new DIW fabrication approach provides capabilities and insights to the additive manufacturing and liquid metal communities to develop advanced materials and devices with exceptional multifunctional capabilities.

Presenting Author: Eric Markvicka University of Nebraska-Lincoln

Presenting Author Biography: Dr. Eric Markvicka is an Assistant Professor of Mechanical and Materials Engineering at the University of Nebraska-Lincoln (UNL). He holds a courtesy appointment in the School of Computing and Department of Electrical and Computer Engineering. Eric is also the director of the Smart Materials and Robotics Laboratory, an interdisciplinary research lab that focuses on the development of soft multifunctional materials. These materials exhibit unique combinations of mechanical, electrical, and thermal properties, which are crucial components for emerging technologies like wearable computing, soft robotics, and robotic materials. Before joining the faculty at UNL, Eric received his B.S. and M.S. in Mechanical and Materials Engineering from UNL, and his M.S. and Ph.D. in Robotics from Carnegie Mellon University.

Authors:

Eric Markvicka University of Nebraska-Lincoln