Session: Rising Stars of Mechanical Engineering Celebration & Showcase

Paper Number: 148577

148577 - Manufacturing Soft Functional Composites Through Mechanically Induced Assembly of Liquid Microstructures in Elastic Films 

This Faculty Early Career Development (CAREER) grant supports research to understand the fundamental processing-structure-property relationships that govern continuous manufacturing and microstructural assembly of liquid metal-based composites for a new class of soft, deformable, and robust functional materials. Soft functional composites consisting of liquid metal droplets dispersed in elastic solids have shown promising capabilities for self-healing and stretchable electronics, soft robots, and thermal interface materials for portable devices. However, these composites are often created in a single batch which limits scalability, and the processing dependence and underlying mechanisms of how liquid metal inclusions deform and assemble during manufacturing is not well known. This research will determine the fundamental inclusion deformation mechanisms and quantify how liquid metal microstructures in soft composites evolve during processing. This research has the potential to guide the realization of new continuous manufacturing strategies for precise and highly controlled mechanical, electrical, and thermal properties in functional soft materials by tuning liquid metal inclusion morphology during processing. The knowledge gained through this research will enable future innovations in electronics and robotics, which benefits national economy and society. Additionally, the research is paired with a broader outreach program and day camp, with an emphasis on first generation students in Southwest Virginia. The outreach program is designed to engage, excite, and develop student interest and skills in manufacturing, soft electronics, and robotics while highlighting STEM career options. 

The specific goal of the research is to determine the processing dependence, underlying mechanisms, and quantitative microstructural origins of how liquid metal inclusions deform and assemble in soft solids. This is achieved through a combination of controlled processing strategies such as film embossing, tentering or stretching, and roll to roll assembly with in-situ electrical characterization and synchronized micro- and nano- computed tomography. This approach provides the processing structure property relationships needed for the advanced manufacturing of soft composites through mechanically induced assembly of liquid microstructures in elastic films. The project aims to determine the fundamental liquid metal inclusion deformation mechanisms and ensuing microstructures as a function of inclusion size, shape, and volume loading. Soft functional composites with programmable properties will be created through reconfigurable microstructures by controlling droplet inclusion shape and connectivity during processing. This project will provide insights on manufacturing and assembly of liquid structures within soft elastic films, introduce new directions to control material properties through reconfigurable liquid microstructures, and enable the design and manufacturing of materials for soft electronics and robots.

Presenting Author: Michael D. Bartlett Virginia Tech

Presenting Author Biography: Michael Bartlett is an Associate Professor and John R. Jones III Faculty Fellow of Mechanical Engineering at Virginia Tech. His research focuses on soft multifunctional materials for deformable electronics and soft robotics, adaptive materials, and switchable and intelligent adhesives. He received his BSE in Materials Science and Engineering from Michigan in 2008 and Ph.D. in Polymer Science and Engineering from UMass Amherst in 2013. After obtaining his Ph.D. he worked as a Senior Research Engineer in the Corporate Research Laboratory at 3M, as a Postdoctoral Fellow at Carnegie Mellon University, and was an Assistant Professor at Iowa State University before joining Virginia Tech in 2020. His research has resulted in publications, patents, media coverage, and awards including an NSF CAREER award, a DARPA Young Faculty Award (YFA) and Director’s Fellowship, a ONR Young Investigator (YIP) Award, the Early Career Scientist Award and Best Paper Award from the Adhesion Society, a 3M Non-Tenured Faculty Award, an ICTAS Junior Faculty Award, and an Outstanding Faculty Award (student nominated) among others. More at: www.bartlett.me.vt.edu

Authors:

Michael D. Bartlett Virginia Tech