(6hb) Liquid Metal Encapsulation: Towards Next Generation Flexible Electronics

The frontiers of technology in the electronics industry are in bendable, lightweight, low-cost devices. Printing technologies for the fabrication of electronic circuits and devices allow for the use of flexible substrates, offer further advantages in terms of speed, cost, material usage, and environmental footprint, and can leverage the existing technology and scale of a $160 billion dollar printing industry. Printing technologies also stand to greatly transform the U.S. Department of Defense’s typical operations using highly customized, low-volume parts needed in remote locations on tight timelines. My research interests are focused on the development of stable, conductive inks, and are balanced between fundamental colloidal science and leveraging this knowledge into practical impact on the advancement and development of manufacturable devices.

Metals such as the eutectic gallium- indium (EGaIn) alloy that are liquid at room temperature are of particular interest for these applications. This class of materials uniquely combines the thermal and electrical conductivity of a metal with the softness and pliability of a liquid, but, in contrast to mercury, are nontoxic with low vapor pressures. However, these metal alloys are not without challenges. Trace amounts of oxygen will react with gallium and form an insulating skin layer, which can be a nuisance as it will adhere to most surfaces and leave behind undesirable residue. This oxide also renders printing from the bulk metal liquid largely unfeasible. The advancement of technologies utilizing these liquid metal materials hinges on the development of new strategies for managing these interfaces and developing them into colloidal dispersions and inks that can be easily processed.

Graphene oxide (GO) and related materials have been shown previously to function as high performance interfacial micro-barriers in emulsified systems. This work expands from previously studied organic/aqueous systems to both metal/aqueous and metal/organic particle dispersions, and demonstrates the first encapsulation of EGaIn liquid metal particle cores by two-dimensional materials. Details discussed will include the role of the continuous solvent and graphene surface chemistries necessary to mediate the self-assembly of the graphene coatings. Such particles can be formulated into inks for implementation into incumbent printing technologies, and engender new technology classes of ultra-soft conductive devices and composites.

Research Interests:

Colloid science, carbon science, nanotechnology, green manufacturing, flexible electronics

Teaching Interests:

Colloid science, introduction to intellectual property, communication skills for scientists and engineers, core classes