Achieving dynamic control over physical properties of materials is an ultimate aspiration of many engineering sciences. The past decades have witnessed phenomenal investment in developing smart materials that can transform and respond to various external stimuli. However, current approaches are mainly off-line and prescribed: design, processing, and characterization of the materials occur only prior to their deployment. In this talk, I will introduce a pathway to enable real-time human-materials interaction by creating advanced digital-physical interfaces that connect humans with materials. To interface with humans, the key challenge is to monitor human signals comfortably and accurately. I will show how epidermal electronics that incorporate high-bandwidth MEMS accelerometers capture multitudes of mechanical and acoustic processes of human body, ranging from broad classes of physiological information to precision kinematics of the core body. To interface with materials, I will describe recent advances in micro/nanomechanics, and how the area of research at the interface between complex microstructures, active metamaterials, and non-destructive testing offers new capabilities for developing programmable matter with digital access to the structure, process, and properties. Based on the two platform technologies, I will conclude by discussing new opportunities in developing human-centered materials intelligence -- with material properties and human signals digitized in a loop, the materials can sense user status or actions, swiftly adapt their microstructures, and henceforth their functional properties on demand. Such an interactive platform will support a rich range of applications in smart materials, digital manufacturing, soft robotics, wearable technologies, medical devices, and many other autonomous and connected systems in general.
Xiaoyue Ni is currently a postdoctoral researcher in the Center for Bio-Integrated Electronics at Northwestern University, where she works with Prof. John A. Rogers on a wearable device for continuous, noninvasive monitoring of human body mechanics and tissue-level diagnosis. She also develops advanced metastructures for active and smart materials. She received her Ph.D. degree in Materials Science from the California Institute of Technology in 2017, where she worked on nanomechanics under the supervision of Prof. Julia R. Greer. Her thesis focused on resolving fundamental physics of dislocation-mediated plasticity. She received her M.S. degree in Materials Science from Caltech in 2014. She holds a B.S. degree in Physics and Mathematics with a Minor in Economics from Marietta College in 2012.