(14ac) 2D Materials Assembly for Stretchable Electronics and Smart Fabrics

Po-Yen Chen, Hibbitt Independent Postdoctoral Fellow
Massachusetts Institute of Technology & Brown University

Postdoctoral Project:

â??Design of Multigenerational Topographies of 2D Building Blocks via Sequential Deformation and Intercalation Templatingâ?
- Under supervision of Ian Y. Wong & Robert H. Hurt, School of Engineering, Brown University

Ph.D. Dissertation:

â??M13 Virus-Enabled Assembly of 3D Nanostructured Composites: Synthesis and Applications in Solar Energy Conversion and Electrochemical Energy Storage Devicesâ?
- Under supervision of Angela M. Belcher & Paula T. Hammond, Department of Chemical Engineering, Massachusetts Institute of Technology (MIT)

Fellowships:

2015, 2016 Hibbitt Engineering Independent Postdoctoral Fellowship (Brown University)
2013, 2014 Eni Energy Fellowship (MIT)
2013 Taiwan National Study Abroad Fellowship
2010 Saudi Aramco Fellowship (MIT)

Research Experience:

Complex surface topographies are of fundamental importance to materials science, physics, biology, and chemistry, impacting applications from catalysis to energy storage and environmental mediation. However, sophisticated design on topographical structures across multiple length scales and over diverse material systems remains challenging. This poster will present our recent works about the creation of multigenerational wrinkled/crumpled textures of versatile materials via sequential deformation and intercalation templating. First, we developed a fabrication that enables extreme mechanical deformation of 2D nanomaterials (e.g., graphene) through multiple cycles of substrate contraction. In each cycle, the compression can be biaxial or unidirectional, leading to a family of different hierarchical wrinkled/crumpled textures. This method achieves a degree of enhancement on structural complexity that far exceeds that of simple one-step deformation processes. The multiscale patterns of graphene show superhydrophobicity (>160°) and improve the electrochemical current densities over 20 times (in comparison with planar coatings). Next, these multigenerational graphene were further utilized as sacrificial templates, and the multiscale surface patterns can be transcribed into other material systems, even beyond 2D nanomaterials (e.g., metal oxides). By harnessing the intersheet gallery spacing of these graphene templates, a wide variety of hydrated metal ions can be uniformly intercalated and immobilized with the functionalities of templates. Subsequently, annealing these composites results in metal oxide thin films that transcribe the original graphene topography with high fidelity. These new textured metal oxide films exhibit enhanced electrochemical and photocatalytic performance over planar films and serve as high-activity electrodes for energy storage and photocatalysis. Overall, these unconventional approaches are broadly applicable for large-area patterning of other 2D nanomaterials and providing a bridging technology that can transcribe textures into other material systems that cannot sustain large deformation.

Research Interests:

My future research interests will focus on large-area patterning of hierarchical surface structures by using various 2D building blocks and study their physiochemical and barrier properties under large mechanical deformation. 2D building blocks, ranging from carbon-based 2D materials to clays and transition metal oxides, display extraordinary chemical, physical and mechanical properties but remain challenging to manipulate them into higher dimensional architectures with large deformability. To address these challenges, I will first continue the work on organizing 2D materials structurally as soft materials while retaining exceptional physiochemical functionality as hard materials. I will emphasize interfacial and surface engineering to facilitate the self-assembly of multiscale, higher-dimensional architectures with highly convoluted features. In the meantime, a systematic approach will be conducted for achieving a control on the wrinkled/crumpled topographies, selective areas, wavelength/width, length scale, amplitude/height, and dynamic patterning. Through above fundamental understanding, I will develop multiple strategies for the fabrication of complex surface patterns of 2D building blocks: 1) wrinkling and crumpling by mechanical deformation, 2) â??snappingâ? surface via confined swelling, 3) origami and kirigami assembly, and 4) 3D printing.

By understanding the factors that produce these higher dimensional structures, it become feasible to design synthetic materials with exactly the kinds of surfaces needed for specific applications, such as stretchable electronics and smart fabrics. By using the proposed fabrication methods, I will apply the convoluted structures of 2D building blocks with high deformability into electromechanical devices, and these surface patterns will retain exceptional physiochemical functionality as well as still provide high performance during reversible stretching. In addition, based on our recent finding, the intersheet gallery spaces of 2D nanomaterials remain unchanged under large deformation, enabling the design of stretchable environmental barriers for the advance of smart fabrics. The combination of mechanical principles (harnessing instabilities of thin films) and materials selection (from 2D nanomaterials to transition metal oxides) leads to a general technological route that can empower great potential to fabricate various flexible and stretchable devices capable of large deformations.

Teaching Interests:

Aside from my research career, I also have extensive teaching experience. As a part of a Hibbitt Postdoctoral Fellowship, I am currently an instructor at Brown University and teach â??Chemical and Biochemical Reactor Designâ?. The duties include providing semester-long lecture series, developing course/experiment materials, and holding office hours. Also, I TAed an undergraduate lecture and laboratory course â??Polymer Science Laboratoryâ? in Chemical Engineering in MIT (for which I was the highest-ranked TA (6.6/7.0) in the semester). In an effort to further improve my teaching skills, I have obtained the Graduate Student Teaching Certificate from MITâ??s Teaching and Learning Laboratory. Lastly, I have mentored over 10 grads/undergrads in both MIT and Brown University. I found each of these experiences to be very rewarding and believe they have helped prepare me for future mentorship and teaching roles.

I am comfortable with teaching any undergraduate core classes in Chemical Engineering; at the graduate level, I could teach Thermodynamics and Kinetics of Chemical Reactions. I would also like to develop a new subject on sustainable energy that focuses on the fundamentals of thermodynamics, chemistry, and transport in a context that is applied to energy systems. This class is ideal for bridging several engineering disciplines and demonstrating to the students the importance and need for multidisciplinary approaches to addressing energy related issues.

Selected Peer-Reviewed Publications:

- 21 peer-reviewed journal articles (11 first-authored papers), 2 patents, 1 book chapter
- *Served as corresponding author

1. P.-Y. Chen*, M. Liu, I. Y. Wong*, R. H. Hurt*, "Multifunctionality of Pressure-Actuated Multiscale Graphene Surface Patterns with Reversible Stretchability." Nano Letters. (In Preparation)
2. P.-Y. Chen*, M. Liu, T. M. Valentin, Z. Wang, R. S. Steinberg, J. Sodhi, I. Y. Wong*, R. H. Hurt*, " Hierarchical Metal Oxide Topographies Replicated from Highly Textured Graphene by Intercalation Templating." ACS Nano. (Under Review)
3. P.-Y. Chen*, Z. Wang, R. H. Hurt*, I. Y. Wong*, "From Flatland to Spaceland: Higher Dimensional Patterning of 2D Nanomaterials." Advanced Materials. (Invited Article)
4. P.-Y. Chen*, J. Sodhi, Y. Qiu, T. M. Valentin, R. S. Steinberg, Z. Wang, R. H. Hurt*, I. Y. Wong*, "Multiscale Graphene Topographies Programmed by Sequential Mechanical Deformation." Advanced Materials 28, 3564 (2016).
1. - Featured as Inside Back Cover
2. - Highlighted in Brown News (1) & (2), IEEE spectrum, and ScienceDaily
5. P.-Y. Chen, N.-M. Dorval Courchesne, M. N. Hyder, J. Qi, A. M. Belcher*, P. T. Hammond*, "Carbon Nanotube-Polyaniline Core-Shell Nanostructured Hydrogel for Electrochemical Energy Storage." RSC Advances 5, 37970 (2015). (Invited Article)
6. P.-Y. Chen, X. Dang, M. T. Klug, N.-M. D. Courchesne, J. Qi, M. N. Hyder, A. M. Belcher*, P. T. Hammond*, "M13 Virus-Enabled Synthesis of Titanium Dioxide Nanowires for Tunable Mesoporous Semiconducting Networks." Chemistry of Materials 27, 1531 (2015).
7. P.-Y. Chen, J. Qi, M. T. Klug, X. Dang, P. T. Hammond*, A. M. Belcher*, "Environmentally Responsible Fabrication of Efficient Perovskite Solar Cells from Recycled Car Batteries." Energy & Environmental Science 7, 3659 (2014).
1. - Highlighted in MIT News (1)&(2), IEEE spectrum, and Washington Post
8. P.-Y. Chen, M. N. Hyder, D. Mackanic, N.-M. D. Courchesne, J. Qi, M. T. Klug, A. M. Belcher*, P. T. Hammond*, "Assembly of Viral Hydrogels for Three-Dimensional Conducting Nanocomposites." Advanced Materials 26, 5101 (2014).
1. - Featured as Front Cover
9. P.-Y. Chen, X. Dang, M. T. Klug, J. Qi, N.-M. Dorval Courchesne, F. J. Burpo, N. Fang, P. T. Hammond*, A. M. Belcher*, "Versatile Three-Dimensional Virus-Based Template for Dye-Sensitized Solar Cells with Improved Electron Transport and Light Harvesting." ACS Nano 7, 6563 (2013).
10. P.-Y. Chen, R. Ladewski, R. Miller, X. Dang, J. Qi, F. Liau, A. M. Belcher*, P. T. Hammond*, "Layer-by-Layer Assembled Porous Photoanodes for Efficient Electron Collection in Dye-Sensitized Solar Cells." Journal of Materials Chemistry A 1, 2217 (2013).
11. P.-Y. Chen, C.-P. Lee, R. Vittal, K.-C. Ho*, "A Quasi Solid-State Dye-Sensitized Solar Cell Containing Binary Ionic Liquid and Polyaniline-Loaded Carbon Black." Journal of Power Sources 195, 3933 (2010).