Mechanics-driven extreme nanomanufacturing
​Fast growing applications of nanostructures in industry, military and consumer products are challenging the current nanomanufacturing technologies, and low-cost, high-efficiency and environment-friendly nanomanufacturing solutions are highly desired. Our projects aim to explore entirely new nanomanufacturing techniques underpinned by mechanics, referred to as extreme nanomanufacturing by my group, to highlight the fundamental ideas that are unusual and extend beyond current practice. ​Topics of interest include self-assembly of 3D structures in liquid, liquid-assisted nanofabrication, mechanics-guided unusual fabrication technique, etc. 
​​
Representative papers: 
(1) ​Yue Zhang, Mengtian Yin, Yongmin Baek, Kyusang Kim, Giovnni Zangari, Liheng Cai, Baoxing Xu. Capillary Transfer of Soft Films. Proceedings of the National Academy of Sciences (PNAS). 117(2020)5210-5216
(2) Dae Seung Wie, Yue Zhang, Min Ku Kim, Bongjoong Kim, Sangwook Park, Young-Joon Kim, Pedro P. Irazoqui, Xiaolin Zheng, Baoxing Xu, and Chi Hwan Lee. Wafer-recyclable, environment-friendly transfer printing for large-scale thin film nanoelectronics. Proceedings of the National Academy of Sciences (PNAS). 115(2018)7236-7244
(3) Yue Zhang, Qingchang Liu, Baoxing Xu. Liquid-assisted, etching-free, mechanical peeling of 2D materials. Extreme Mechanics Letters.16(2017)33

Mechanics design and manufacturing of biomedical devices
Micro/nanofluidic devices and systems have attracted ever-growing attention in healthcare applications over the past decades due to low-cost yet easy-customizable functions with the demand of only a small volume of sample fluid. The continuous development, in particular, supported by the emerging of new materials, capable of meeting critical needs in next-generation, wearable, and multifunctional biomedical devices for at-home, personalized healthcare monitoring is challenging the principles and strategies of structural design, manufacturing, and their seamless integration. Our work is to develop mechanics-centered design and processing strategies and approaches for immediate applications in biomedical engineering and healthcare monitoring. ​Topics of interest include pain management electronic devices and porous materials-liquid based sensors and actuators.

Representative papers:
(1) Mingyu Sang, Kyowon Kang, Yue Zhang, Haozhe Zhang, Kiho Kim, Myeongki Cho, Jongwoon Shin, Jung-Hoon Hong, Taemin Kim, Shin Kyu Lee, Woon-Hong Yeo, Jung Woo Lee, Taeyoon Lee, Baoxing Xu and Ki Jun Yu. Ultra-high Sensitive Au-doped Silicon Nanomembrane Based Wearable Sensor Arrays for Continuous Skin Temperature Monitoring with High Precision. Advanced Materials. 2021, 2105865
(2) Kyunghun Kim, Ho Joong Kim, Haozhe Zhang, Woohyun Park, Dawn Meyer, Min Ku Kim, Bongjoong Kim, Heun Park, Baoxing Xu, Pete Kollbaum, Bryan W Boudouris, Chi Hwan Lee. All-printed stretchable corneal sensor on soft contact lenses for noninvasive and painless ocular electrodiagnosis. Nature Communications 12 (2021) 1544
​(3) Mengtian Yin, Li Xiao, Qingchang Liu, Sung‐Yun Kwon, Yi Zhang, Poonam R Sharma, Li Jin, Xudong Li, Baoxing Xu. 3D Printed Microheater Sensor‐Integrated, Drug‐Encapsulated Microneedle Patch System for Pain Management. Advanced Healthcare Materials. 8(2019)1901170

Nanomechanics in extreme conditions
Material and structural functionality are closely associated with their mechanical properties at the nanoscale and service environments, and in turn, the understanding of their relationship may lead to novel design and nanomanufacturing strategies of structures and devices with unprecedented functions. Our recent research focuses on mechanics of solid materials (e.g. mechanical deformation, wrinkling/buckling, self-assembly) at solid-liquid interfaces in a nanoconfined environment. Topics of interest include mechanics of liquids in nanoconfinements, nanofluidics in response to environments (e.g. temperature, electrical field, force, pH value), mechanical deformation and assembly by interfaces, etc.  

Representative papers:
(1) Yuan Gao, Mingzhe Li, Yue Zhang, Weiyi Lu, Baoxing Xu. Spontaneous Outflow Efficiency of Confined Liquid in  Hydrophobic Nanopores. Proceedings of the National Academy of Sciences (PNAS). 117(2020)25246-25253
​(2) Qingchang Liu, Jiaxing Huang, Baoxing Xu. Evaporation-Driven Crumpling and Assembling of Two-Dimensional (2D) Materials: A Rotational Spring–Mechanical Slider Model. Journal of the Mechanics and Physics of Solids.133(2019)103722
(3) Weizhu Yang, Qingchang Liu, Zhufeng Yue, Xiaodong Li, Baoxing Xu. Rotation of Hard Particles in a Soft Matrix. Journal of the Mechanics and Physics of Solids.101(2017)285-310

Engineering design of functional structures by mechanics
Engineering design of materials and structures has evolved radically from earliest employment of single phase materials with a focus on optimization of geometric shapes to recent multiphase materials with tactful integration and assembly in both geometric shapes and material domains. Our research aims to compartmentalize and leverage the underpinned fundamental (interface) mechanics principles that could enable creations of intelligent new design concepts and approaches of functional materials and structures capable of being readily manufactured for desired applications. Topics of interest include soft-hard integrations, nanoporous materials, nanopore-liquid composite materials, etc.

Representative papers: 
(1) Xu Wang, Qingchang Liu, Siyao Wu, Baoxing Xu, Hangxun Xu. Multilayer Polypyrrole Nanosheets with Self‐Organized Surface Structures for Flexible and Efficient Solar–Thermal Energy Conversion. Advanced Materials. 31(2019)1807716
(2) Weizhu Yang, Qingchang Liu, Zongzhan Gao, Zhufeng Yue, Baoxing Xu. Theoretical Search for Heterogeneously Architected 2D Structures. Proceedings of the National Academy of Sciences (PNAS).115(2018)7245-7254
(3) Weizhu Yang, Zongzhan Gao, Zhufeng Yue, Xiaodong Li, Baoxing Xu. Hard-particle rotation enabled soft–hard integrated auxetic mechanical metamaterials. Proceedings of the Royal Society A. 475(2019)20190234

Mechanical-thermal coupling and correlation in nanomaterials
Structures and devices enabled by nanomaterials such as flexible electronics and thermal interface materials usually experience large mechanical deformation to achieve an intimate conformal contact with surface of interest and to coordinate complex motions in use. The large mechanical deformation will lead to a strong coupling and correlation between thermal transport and mechanical deformation in nanomaterials, which substantially challenge device/structural performance. Our research aims to elucidate their strong coupling mechanism and correlation behavior in nanomaterials and explore optimization designs of structures and devices with mechanically tunable thermal properties. Topics of interest include thermal transport of mechanically deformable materials, stretchable thermal structures and thermal response based mechanical sensors and actuators. 

Representative papers:
(1) Qingchang Liu, Yuan Gao, Baoxing Xu. Transferable, Deep-Learning-Driven Fast Prediction and Design of Thermal Transport in Mechanically Stretched Graphene Flakes. ACS Nano. 15(2021)16597-16606
(2) Yuan Gao, Baoxing Xu. van der Waals Graphene Kirigami Heterostructure for Strain-Controlled Thermal Transparency. ACS Nano. 12(2018)11254-11262
​(3) Yuan Gao, Qingchang Liu, Baoxing Xu. Lattice Mismatch Dominant Yet Mechanically Tunable Thermal Conductivity in Bilayer Heterostructures. ACS Nano. 10(2016)5431-5439​