Professor René Wasserman Award 2019 - Wei Yan

"For his important and impactful contributions to the fields of flexible electronics and advanced fiber materials. His research has led to the development of flexible fiber-based devices, and textiles, with electronic and optoelectronic properties on par, or better than, conventional wafer-based systems."

Fibers, ancient yet largely underdeveloped forms, are the common building blocks of a broad spectrum of product forms from textiles to aircraft constructs. While ubiquitous, these fibers are produced at scale from essentially single materials. The preform-to-fiber thermal drawing technique that integrates various functional materials into a single strand of fiber, has been emerged as an unprecedentedly compelling platform for enabling fibers to evolve into functional devices and smart systems. These multimaterial fibers are able to see, hear, sense, communicate, store and convert energy, modulate temperature, monitor health and dissect brains. Thus far however, control over the microstructure of two types of technologically important materials (metals and semiconductors) is poorly understood in multimaterial fibers, which restricts their potential applications.

Here, Dr. Wei Yan developed some unique approaches capable of controlling the crystal nucleation and growth of the in-fiber semiconductor. This resulted in the first monocrystalline semiconducting nanowire-based optoelectronic fiber and fibers with crystallographically aligned semiconductors. Controlling over the interplay between fluid instabilities and crystallization dynamics, ultralong nanoscale in-fiber metallic glasses with arbitrary transverse geometries, feature size spanning three orders of magnitude, and extreme aspect ratios >10¹⁰ were produced. Unprecedented applications in sensing, imaging, smart textiles, medical devices and neuroscience using these novel fibers were demonstrated.