Mode: Mixed
Under strain, the physical properties of semiconductors can undergo significant changes. However, bulk semiconductor crystals are usually rigid and brittle, making it challenging to achieve high strain levels. Our experiments show that by microfabricating semiconductors like silicon and diamond into micro/nanostructures, they can approach their theoretical strength and sustain ultralarge elastic deformation, opening a new pathway for deep elastic strain engineering of semiconductors via nanomechanics. To realize such strain-engineered device applications, we microfabricated single-crystalline diamond microbridge arrays and achieved sample-wide uniform elastic strains of up to ~10% under uniaxial tensile loading. This ultralarge strain significantly reduced diamond’s bandgap by >2eV or converted diamond from an indirect to a direct bandgap semiconductor, demonstrating great potential for wide bandgap semiconductors and optoelectronics. Moreover, we have extended deep elastic strain engineering to two-dimensional material systems. This includes pioneering the first tensile and shear tests on free-standing monolayer 2D materials, such as graphene, hexagonal boron nitride and Transition Metal Dichalcogenides, as well as their homo- and heterostructures (e.g., twisted bilayer graphene). These studies not only reveal the anomalous nanomechanical properties of 2D materials, but also underscore the potential of elastic strain engineering (up to ~6%) for tuning 2D electronic and optoelectronic devices.
Professor Yang Lu, Associate Dean of Engineering, Chair Professor of Nanomechanics, Kingboard Professor in Materials Engineering and HKU-100 Scholar at The University of Hong Kong. His main research areas include micro/nano mechanics and advanced manufacturing. He has published more than 200 articles in leading academic journals including Science, Nature Nanotechnology, Nature Materials, Nature Communications and Science Advances. Professor Lu serves as an associate editor for the international journal Materials Today, as well as a board member for academic journals such as National Science Review, Science China Technological Sciences, and Acta Mechanica Sinica.Prof. Lu is a recipient of UGC Early Career Award 2013/14, the inaugural NSFC Excellent Young Scientists Fund (Hong Kong and Macau) 2019 and RGC Research Fellow scheme (RFS) 2020/21. He is an elected member of the Hong Kong Young Academy of Sciences (YASHK) in 2022, and elected fellow of Hong Kong Academy of Engineering (Young Member Section) in 2025.
Clean water and clean air are vital for public health. This project focuses on developing high-efficiency and environmentally sustainable filters for removing harmful air/water pollutants. The team has developed novel architectures and functionalities for the filters to achieve high permeance, high removal efficiency, and excellent reusability.
