Education:

  • Sc.D., Massachusetts Institute of Technology, 2003
  • Ph.D.,Tsinghua University, China, 1999
  • B.S., Tsinghua University, China, 1994

Research Areas and Descriptors

Mechanics of Materials; Soft active materials; 3D/4D printing technology; 3D printing of active materials and structures; Design of active materials and structures; Recyclable polymer systems; Experimental characterization and constitutive modeling of nonlinear thermoviscoelastic behaviors of polymers; Polymer physics and mechanics; Photo-mechanics of light activated polymers; Shape memory polymers; Nonlinear finite element analysis; Mechanics of soft tissue growth.

Background

Dr. Qi joined Tech in January 2014 as an associate professor and was promoted to a full professor in March 2016. Prior, he was an associate professor at University of Colorado Boulder (2004-2013) and was a postdoctoral fellow at MIT (2003-2004). He is currently seeking talented undergraduate and PhD students and postdocs.

Research

Dr. Qi’s research falls in the general area of finite deformation multiphsyics modeling of soft active materials. The material systems include: shape memory polymers, shape memory elastomeric composites, light activated polymers, covalent adaptive network polymers (or vitrimers). Particularly, he is interested in understanding and modeling the evolution of material structure and mechanical properties of these materials under environmental stimuli, such as temperature, light, etc, and during material processing, such as 3D printing. To assist understanding of mechanical properties, his group routinely conducts thermomechanical or photo-mechanical experiments. Constitutive models developments are typically based on the observations from these experiments. The ultimate goal of the constitutive models is to integrate them with finite element through user material subroutines so that these models can be used to solve complicated 3D multiphysics problems involving nonlinear mechanics.

His current research projects include 4D printing of active materials, mechanics in 3D printing technology, active polymer design and manufacturing, reprocessing and recycling polymers. For 3D/4D printing, his group is developing 3D hybrid printing methods by using a variety of 3D printing technologies, such as inkjet, Stereolithography (SLA), Direct Ink Write (DiW), Fused Deposition Modeling (FDM), to print active and functional materials, such as shape memory polymers, liquid crystal elastomers, conductive polymers, epoxies, and cellulose nanocrystals. For reprocessing and recycling polymers, his group is developing methods and technologies to recycling thermosetting polymers and composites, such as fiber reinforced epoxy composites. These projects are conducted through supports by NSF and AFOSR, and through collaborations with Singapore University of Technology and Design (SUTD), and Air Force Research Laboratories (AFRL).

 

  • ASME Fellow (2015)
  • The Woodruff Faculty Fellow (2015)
  • J. T. Oden Faculty Fellowship, UT Austin, (2012)
  • AFRL summer faculty fellowship (2010-2012)
  • Mechanical Engineering Outstanding Research Award (2009)
  • Mechanical Engineering Chair Faculty Fellow (2008)
  • NSF Career Award (2007)
  • Woodward Outstanding Mechanical Engineering Faculty (2006-2007)

Selected:

  • Yu, K., Shi, Q., Li, H., Jabour, J., Yang, H., Dunn, M.L., Wang, T., and Qi, H.J., 2016. Interfacial Welding of Dynamic Covalent Network Polymers, Journal of Mechanics and Physics of Solids, in press.
  • Mao, Y., Ding, Z., Yuan, C., Ai, S., Isakov, M., Wu, J., Wang, T., Dunn, M.L., Qi, H.J., 2016. 3D Printed Reversible Shape Changing Component with Stimuli Responsive Materials. Scientific Reports, in press
  • Wu, J., Yuan, C., Ding, Z., Isakov, M., Mao, Y., Wang, T., Dunn, M.L., Qi, H.J.,  2016. Multi-shape active composites by 3D printing of digital shape memory polymers. Scientific Reports, in press.
  • Yang, H., Yu, K., Wei, Y., Guo, Y., Qi, H.J., 2016. Molecular Dynamics Studying on Welding Behavior in Thermoset Polymers due to Bond Exchange Reactions. RSC Advances, 6, 22476–22487.
  • Taynton, P., Ni, H., Zhu, C., Yu, K., Loob, S., Jin, Y., Qi, H.J., and Zhang, W., 2016. Repairable Woven Carbon Fiber Composites with Full Recyclability Enabled by Malleable Polyimine Networks, Advanced Materials, in press.
  • Mao, Y., Robertson, J.M., Mu, X., Mather, P., Qi, H.J., 2015, Thermoviscoplastic behaviors of anisotropic shape memory elastomeric composites for cold programmed non-affine shape change, Journal of Mechanics and Physics of Solids, 85:219-244.
  • Mao, Y., Yu, K., Isakov, M., Wu, J., Dunn, M.L., and Qi, H.J., 2015. Sequential Self-Folding Structures by 3D Printed Digital Shape Memory Polymers, Scientific Reports, 5:13616.
  • Yang, H., Yu, K., Mu X., Shi, X., Wei, Y., Guo, Y. Qi, H.J., 2015. A molecular dynamics study of bond exchange reactions in covalent adaptable networks. Soft Matter, 11, 6305-6317.
  • Zhao, Q., Qi, H.J., Xie, T., 2015. Recent Progress in Shape Memory Polymer: New Behaviors, Enabling Materials, and Mechanistic Understanding, Progress in Polymer Science, 49-50:79-120.
  • Mu, X., Sowan, N., Tumbic, J.A., Bowman, C.N., Mather, P.T., Qi, H.J., 2015. Photo-Induced Bending in a Light-Activated Polymer Laminated Composite, Soft Matter, 11(13), 2673-2682.
  • Ge, Q., Dunn, C., Qi, H.J., Dunn, M.L., 2014. Active Origami by 4D Printing, Smart Materials and Structures, 23, 094007-15. (Selected as Highlights of 2014)
  • Ma, J., Mu, X., Bowman, C.N., Sun, Y., Dunn, M.L., Qi, H.J., Fang, D.N., 2014. A Photoviscoplastic Model for Photo Activated Covalent Adaptive Networks. J. Mech. Phys. Solids., 70, 84-103.
  • Taynton, P., Yu, K., Shoemaker, R., Jin, Y., Qi, H.J., Zhang, W., 2014. Heat or water driven self-healing in a highly-recyclable covalent network polymer, Advanced Materials, v26, 23:3938-3942.
  • Yu, K., Ge, Q., Qi, H.J., 2014, Reduced Time as a Unified Parameter Determining Fixity and Free Recovery of Shape Memory Polymers, Nature Communication, 5:3066.
  • Ge, Q., Qi, H.J., Dunn, M.L., 2013, Active Materials by 4D Printing, Applied Physics Letter, 103, 131901. (Reported by NPR, ABC, and many other medias)
  • Jennie Ryu, J., D’Ameto, M., Cui, X., Long,K.N., Qi, H.J., Dunn, M.L., 2012. Photo-Origami-Bending and folding polymers with light, Applied Physics Letter, 100, 161908.
  • Ge, Q., Luo, X., Rodriguez, E.D., Zhang, X., Mather, P., Dunn, M.L., Qi, H.J., 2012, Thermo-mechanical Behaviors of Shape Memory Elastomer Composites, J. Mech. Phys. Solids., v60, 67-83.
  • Westbrook, K.K., Kao, P.H., Castro, F., Ding, Y., Qi,H.J., 2011. A 3D Finite Deformation Constitutive Model for Amorphous Shape Memory Polymers: A Multi-Branch Modeling Approach for Nonequilibrium Relaxation Processes. Mechanics of Materials, v43: 853-869.
  • Wang, A., Hansen, C, Ge, Q., Maruf, S. H.,  Ahn, D. U., Qi, H.J., and Ding, Y., 2011, Programmable, Pattern-Memorizing Polymer Surface, Advanced Materials, 23:3669-3673.
  • Long, K. N., Scott, T. F., Qi, H. J., Bowman, C. N., and Dunn., M. L., 2009. Photomechanics of Light-Activated Polymers, J. Mech. Phys. Solids, 57:1103-1121.
  • T. D. Nguyen, H. J. Qi, F. Castro, K.N. Long, 2008. A thermoviscoelastic model for amorphous shape memory polymers: Incorporating structural and stress relaxation, J. Mech. Phys. Solids,56:2792-2814.
  • H.J. Qi, T.D. Nguyen, F. Castro, C. Yakacki, R. Shandas, 2008. Finite Deformation Thermo-Mechanical Behavior of Thermally Induced Shape Memory Polymers, J. Mech. Phys. Solids, 56:1730-1751.