Designing Activators and Monomers for 3D Printed Chemically Coalescing Liquid Metal Polymer Composites

Project Description

Room temperature liquid metals are ideal soft conductors. By embedding them into elastomeric matrices they can maintain high electrical conductivity large cyclic without affecting the mechanical properties of the host matrix. Their low viscosity and high surface tension allow them enable fast responses to mechanical deformations. They also exhibit negligible vapor pressure, low levels of toxicity, and are inherently softer than any solid, making them suitable for interfacing with delicate materials. However, the complex rheological properties associated with liquid metals make them challenging to process into 2D and 3D geometries, limiting their use in functional devices.

To address this challenge, recent progress has been made by synthesizing liquid metal emulsions, which are capable of being being 2D and 3D printed through a variety of techniques. However, the resulting structures are not conductive, owing to the non-conductive native oxide surrounding each droplet. These structures can be made conductive through a large mechanical stimulus, laser ablation, or high temperature furnace, which makes it challenging to integrate these emulsions with other materials. Recently, our group has made progress on formulating liquid metal emulsions with chemical activators that render conductive structures through a low thermal stimulus (80 C). However, these emulsions still require packaging and are limited to specific packaging chemistries. This REU will address this challenge by developing new chemically active 3D printable liquid metal emulsion polymer composites that simultaneously form conductive networks and a cross-linked polymer composite through a low temperature or light stimulus.

Mentors

Chloe Kekedjian & Stephanie Zopf

2023 Timeline

Weeks 1-2: Become familiarized with the lab, background work, and get trained on synthesizing and 3D printing liquid metal emulsions
Weeks 3-8: Synthesize new emulsion inks from our pre-determined list of activator and monomer candidates. Characterize conductivity, mechanical properties, and chemical reactions of resulting emulsions
Weeks 9-10: Synthesize results from study into a report and poster