Materials Horizons Emerging Investigator Series: Dr Jie Xu, Argonne National Laboratory, USA

Jie Xu is a scientist at Argonne National Laboratory. Her research focuses on engineering chemical and morphological structures of novel electronic materials using artificial intelligence and robotics systems, with the aim of precisely controlling their solid-state properties (e.g., electronic, optical, mechanical). Her research started from the fundamental aspects of polymer glass, understanding material packing structure and dynamics. Subsequent postdoctoral training at Stanford University applied her background in polymer physics to the emerging field of skin-like electronics, with the development of a new class of polymer-based stretchable electronic material and the realization of integrated, intrinsically stretchable transistors and circuits. Recognizing the inefficiency of relying solely on human labor, she spearheaded the development of Polybot, an AI-integrated laboratory at Argonne, to accelerate polymer research. Her expertise in the field has been recognized by several prestigious programs, such as the https://www.youtube.com/watch?v=pyv2GgFhP2s, https://www.technologyreview.com/innovator/jie-xu/, https://www.newsweek.com/2021/12/24/americas-greatest-disruptors-budding-disruptors-1659089.html, and the https://pmsedivision.org/2023/04/2023-early-stage-investigators-announced/.

Read Jie Xu's Emerging Investigator Series article ‘Real-time correlation of crystallization and segmental order in conjugated polymers’ ( https://doi.org/10.1039/D3MH00956D ) and read more about her in the interview below:

MH: Your recent Materials Horizons Communication looks to understand how highly anisotropic conjugated polymers form segmentally ordered structures with ongoing crystallization. How has your research evolved from your first article to this most recent article, and where do you see your research going in the future?

JX: My initial work during my PhD period delved into fundamental aspects of polymer glass, exploring chain-packing structure and segmental motion. This likely laid the groundwork for understanding the structural dynamics and behavior of polymer materials for my future endeavors. Motivated by an unwavering desire to apply science, I set my sights on electronic functional conjugated polymers.

In this domain, I applied concepts from polymer physics to realize integrated, intrinsically stretchable transistors designed for skin electronics. The development of these conjugated polymers underscored the significance of precise control over their local morphological ordering for unlocking their full potential. Traditional approaches have relied on crystallinity as a measure of ordering, yet this no longer suffices for many newly developed high-performance conjugated polymers. In an innovative pursuit, this research harnesses the power of a unique fusion between ultra-fast scanning calorimetry (FSC) and micro-Raman spectroscopy to unravel this enigma. It became evident that chain segmental order, rather than crystalline order, dictates mechanical ductility and electronic performance. Looking ahead to my future research, given the inherent complexity and extensive search space in developing electronic polymers, I recognized the inefficiency of relying solely on human labor and cognitive capabilities. Motivated by this, I embarked on a quest for a new paradigm in research. This vision led me to spearhead a team effort at Argonne, where we are developing an AI-integrated automated laboratory, known as Polybot, to infuse AI/ML into the experimentation process and accelerate polymer research.

MH: What aspect of your work are you most excited about at the moment?

JX: We know that the process of discovering new polymers with desired properties can be time-consuming and resource-intensive. Therefore, I am eager to leverage the power of AI and robotics to revolutionize this process and make it accessible to all researchers.

MH: In your opinion, what are the most important questions to be asked/answered in this field of research?

JX: In the pursuit of designing conjugated polymers with targeted properties, such as a specific bandgap or enhanced stability, is there a comprehensive and data-rich “handbook” available, along with established design principles, to guide the formulation of the desired polymer chemical structures and processing conditions? The development of conjugated polymers with optimal characteristics involves navigating a vast design space, encompassing the fine-tuning of individual polymer-chain structures, the hierarchical assembly of morphologies, and the construction of multilayer architectures in applications. Despite the complexity of this design space, a complete map detailing the relationships between structure, morphology, and properties (or the connections between formulation, processing, and functions) is yet to be fully established.

MH: What do you find most challenging about your research?

JX: One of my significant challenges is the inherent nature of scientific research itself – the quest for answers to complex questions that often lead to more questions. This continuous exploration requires patience, perseverance, and resilience. The process of designing and conducting experiments, analyzing data, and interpreting results can be arduous and filled with uncertainties. However, I view these challenges as opportunities for growth and innovation. They push me to think critically, develop creative problem-solving skills, and refine my research methodologies.

MH: In which upcoming conferences or events may our readers meet you?

JX: ACS Spring 2024, MRS Spring 2024, and the APS March Meeting 2024.

MH: How do you spend your spare time?

JX: I spend most of my spare time on activities centered around my family, including travelling, gardening, enjoying movies, and cooking.

MH: Can you share one piece of career-related advice or wisdom with other early-career scientists?

JX: My advice to early-career scientists revolves around understanding and harnessing the power of time, being patient and persistent in their pursuits, managing time effectively, cultivating relationships, investing in continuous learning, and maintaining a healthy work–life balance.

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