Jim: Could you tell us about this material?
Eric: The rubber composite is composed of microscopic droplets of eutectic gallium-indium embedded inside of a soft silicone rubber. In contrast to most particle-filled composites, the liquid-phase composite is softer than the unfilled rubber, and is electrically insulated after it has cured, even for high volume loadings (up to 50%).
Jim: Was this the first time you worked with liquid metal (gallium-indium)?
Eric: No, liquid metal (gallium-indium) was used in several of my recent projects. I’ve used liquid metal (gallium-indium) to increase the dielectric constant of soft silicone elastomers while preserving the mechanical properties of the host elastomer for electrical wiring in soft-matter printed circuit boards. Here we patterned the liquid metal (LM) circuit wiring using UV laser micromachining [DOI: 10.1021/acsami.7b05522], and most recently we were able to create visually imperceptible, stretchable LM circuit wiring for use in a heads up display to warn of potential environmental hazards.
Jim: I have some papers to check out! In the next post, Indium will discuss how easy it is to make these flexible circuits using a commercially available plotter. We’ll see you then…
