Dr. Xiaoyu Zheng
Assistant Professor, Department of Mechanical Engineerin, Virginia Tech
Optical 3D printing processes for lightweight, scalable 3D metamaterials
It has been a long research and engineering pursuit to create lightweight and
mechanically robust and energy efficient materials with interconnected porosity.
These cellular materials are desirable for a broad range of applications including
structural components, lightweight transportation, heat exchange, catalyst
supports, battery electrodes and biomaterials. However, the required outstanding
properties have remained elusive on lightweight materials (<10kg/m3),
constrained by the inherent coupling of material properties and the lack of
suitable processes to generate these artificial materials. For example, graphene
aerogels have among the lowest record densities ~1kg/m3, but their strength
have been degraded to tens to hundreds of Pascal (<10^-8 of that of carbon
nanotubes). The attainment of low density has come with a price — – significant
reduction of bulk scale properties. In this talk, I will first overview Virginia Tech’s
research’s trusts on advanced manufacturing capabilities and novel materials by
design. I will then focus on our recent efforts on design and manufacturing of
lightweight materials with controlled three-dimensional architectures from the
macroscale to nanoscales using a suite of unique optical additive manufacturing
approaches. These 3D bulk metamaterials (polymer, metal, ceramic and
combinations thereof) possess weight density comparable to that of carbon
aerogel, but with over 10^5 higher stiffness and strength. By designing and
studying their hierarchical architectures, material compositions and feature sizes
spanning multiple length-scales, we create a wide range of low density materials
with programmable properties including tunable stiffness and strength, high
fracture tolerance as well as addressable deformation capabilities. With the
possibility of incorporating precise control of topological architectures across
unprecedented disparate length-scale sets, we enter into a paradigm where
nanoscale material properties can be harnessed and made accessible in large
scale objects, opening a wide range of applications of these materials in energy,
health care and flexible electronics.
Xiaoyu (Rayne) Zheng is an Assistant Professor of Mechanical Engineering and
directs the Advanced Manufacturing and Metamaterials Laboratory at Virginia
Tech. He also holds an affiliate position at the Macromolecules and Innovation
Institute at Virginia Tech. Prior to joining Virginia Tech in September 2015, he
had been a Principle Investigator and Member of Technical Staff with the
Materials Engineering Division, DOE Lawrence Livermore National Laboratory,
Livermore, California since 2011. He received his Ph.D. degree in Mechanical
Engineering from Boston University in 2011 with the Best Dissertation Award.
From 2011 to 2015, worked at a member of technical staff at Lawrence
Livermore National Laboratory developing low density hierarchical metamaterials
and advanced additive manufacturing processes capable of three-dimensional
features at the micro- and nano-meter scale with a range of materials from
polymer, metal, ceramic to composites. The key focus of Zheng’s research at
Virginia Tech is to combine a suite of novel additive manufacturing (3D printing)
technologies and design tools to enable the design, analysis, and fabrication of
multi-scale, three-dimensional materials and systems that possess extraordinary
and unique capabilities for lightweight structural, energy and biological
applications. He has published over 40 journal articles, proceeding papers and
book chapters including Science and Nature Materials where his most recent
research on 3D micro-architected materials were both featured on the front
pages. Zheng received Best Paper Award at 2010 IEEE Sensor Conference,
Best Poster Award at Materials Research Society and the President Award at
Boston University and Directorate Publication Excellence Award at Lawrence
Livermore National Laboratory in 2013 and 2015. His work has been widely
reported by R&D Magazine, Science Daily, MIT front page, MIT Technology
Review, Materials Today, Nano Today, Material Research Society Bulletin,
American Physics Society etc.