Air Force Research Laboratory (AFRL)
Hosted by Professor Mark Hersam
Sponsored by Northwestern University and the Air Force Center of Excellence (AFCOE)
Gallium liquid metal alloys (GaLMAs) are room temperature fluidic conductors that have been used to create a variety of paradigm shifting concepts in stretchable and reconfigurable electronics. Like many other metals, a thin native oxide skin forms spontaneously on the surface. Unlike most other metals at room temperature though, the underlying metal remains fluid with the skin serving as a viscoelastic solid which allows remarkably unprecedented fluidic structures to be constructed. It also provides a barrier of sorts to the underlying fluid alloying with solid metal electrodes. However, this oxide can have detrimental effects to fluidic behavior in microchannels because it tends to adhere to channel walls. The most reported response to date has been to utilize strongly acidic or basic co-fluids to react with the oxide and etch it away. This approach results in the need to replenish the chemical reactants as well as remove detrimental byproducts from the system. This also leads to significant alloying as the metallic fluids directly contact solid electrodes. Our work has focused on controlling the surface chemistry of the fluids to enable the novel capabilities that gallium alloys promise in flexible, stretchable, self-healing, and reconfigurable electronics.
Dr. Christopher Tabor is a Materials Research Scientist in the Functional Materials Division, Materials and Manufacturing Directorate, Air Force Research Laboratory, Air Force Materiel Command, Wright-Patterson Air Force Base, Ohio. He performs research in the area of Stretchable and Reconfigurable Electronics and is the AF focal point for gallium liquid metal alloys as well as a recognized expert in plasmonic nanomaterials. One of Dr. Tabor’s primary activities is leading an AFRL wide program investigating room temperature liquid metal alloys for structurally integrated reconfigurable and stretchable RF electronics. Dr. Tabor has published 18 peer-reviewed journal articles in the area of optical and electronic properties of metals.