Session: 20-17-01: Rising Stars of Mechanical Engineering

Paper Number: 172159

Career: Manufacturing of Solid Particle-Liquid Metal Mixtures for Soft Robotics and Stretchable Electronics 

This Faculty Early Career Development (CAREER) grant establishes a scalable manufacturing approach for incorporating diverse solid particle additives into room temperature liquid metals by controlling their reactivity and wetting characteristics through an interfacial engineering approach. This work provides new fundamental knowledge that enables the creation of a novel class of multiphase conductive pastes with customizable physical, rheological, and chemical properties. The enhanced properties increase the suitability of using liquid metal pastes for extrusion-based three-dimensional (3D) printing and lead to new applications in soft robotics and stretchable electronics, which contribute to the economic and societal advancement of U.S. manufacturing. The solid particle-liquid metal mixtures are suitable materials for additive manufacturing of a variety of applications such as control systems, soft matter actuators, and distributed sensors. The research is complemented by new learning modules that seek to actively engage students across the educational spectrum by integrating entrepreneurial literacy with research-based activities focused on additive manufacturing, materials processing, and digital modeling. These modules are delivered through local programs and via a mobile science lab to schools and teachers across Nebraska and elsewhere to enhance classroom learning for ethnically, geographically, and socio-economically diverse students.

The goal of this research is to establish a universal strategy for incorporating solid particle additives into liquid metals to enhance their physical and rheological properties without compromising their fluidic attributes. Typically, the solid particle additive is a metal such as nickel, tungsten, or copper and the liquid metal is gallium or its compounds. The high reactivity and cohesive energy of gallium-based liquid metals offer challenges at the solid-liquid interface, which are overcome through an interfacial engineering approach where an intermediate layer is introduced to concurrently act as a corrosion barrier and wetting agent. The solid particle-liquid metal mixtures are created by mixing via mechanical shear under controlled conditions. The physical properties, rheological behavior, and chemical stability are subsequently characterized to establish the process-property-performance relationships to understand how the particle composition, volume loading, and size affect the properties and performance of the particle-liquid metal mixtures. The improved properties, enhanced chemical stability, and ability to pattern structures in three-dimensions enable particle-liquid metal mixtures to take a range of forms, from discrete inclusions in composite materials to patterned liquid networks. This research enables the design and manufacturing of materials and structures tailored for soft structures, devices and systems inspired by biology.

This project is jointly funded by the Advanced Manufacturing (AM) Program, the Established Program to Stimulate Competitive Research (EPSCoR), and the Civil, Mechanical and Manufacturing Innovation (CMMI) Division.

Presenting Author: Eric Markvicka University of Nebraska

Presenting Author Biography: Dr. Eric Markvicka is the Robert F. and Myrna L. Krohn Associate Professor of Mechanical and Materials Engineering at the University of Nebraska-Lincoln (UNL). There, he also holds a courtesy appointment in the School of Computing and the Department of Electrical and Computer Engineering. At UNL Prof. Markvicka directs the Smart Materials and Robotics Laboratory, an interdisciplinary research lab that is creating multifunctional soft materials that exhibit a unique combination of mechanical, electrical, acoustic, and thermal properties. These materials are critical components for the emerging fields of wearable computing, soft robotics, and robotic materials. Prof. Markvicka has is a senior member of the National Academy of Inventors and has received the 2024 NSF CAREER award, ASME Rising Star of Mechanical Engineering award, 2024 College of Engineering Edgerton Innovation Award, 2023 College of Engineering Excellence in Research Award, and 2021 NUtech Ventures Emerging Innovator of the Year award. 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