Li-Hsin (Leo) Han, PhD, is an Associate Professor in the Department of Mechanical Engineering and Mechanics at Drexel University. His research experience includes polymeric micro/nano-fabrication, biomaterial design, tissue engineering, rapid prototyping, free-form fabrication, polymer microactuators and photonics. Han received both his BS and MS in Mechanical Engineering (1996 and 1998) from National Taiwan University. He worked as a 2nd lieutenant for military service (1998-2000), and then a patent engineer in the industry (2000-2002). He received his PhD in Mechanical Engineering from UT Austin in 2009, and then the Postdoctoral training at Stanford University School of Medicine from 2010 to 2014. Han joined the faculty at Drexel University in 2014.
Degrees / Education
- PhD, The University of Texas at Austin
3-dimensional (3D) polymer microstructures have broad applications, ranging from fuel cells to biomedical implants. Top-down and bottom-up fabrications are the most common strategies for making these microstructures, and have been implemented by photolithography and molecules self-assembly. However, the current technology is often associated with low yield, small production scales and long fabrication time, which led to limited industrial applications. To overcome these limitations, we created the Building-blocks Strategy to facilitate 3D polymer microstructures formation.
By using cost-effective methods such as wet-spinning and emulsification, spherical, rod-like and ribbon-shaped building-blocks were produced at large quantity with micron-sized features and crosslinkable chemicals, and were assembled covalently into complex 3D microstructures, including interconnected porosity and micro-channels. Currently we are investigating the following topics: (a) how do shapes, stiffness and chemical properties influence the self-alignments and cross-linking among building blocks; (b) what fabrication platforms can be used to better customize the building-blocks; and (c) to what applications can we best apply the building-block strategy.
Areas of Study
- May 2016 Investigator Award of the Society for Biomaterials at the 10th World Biomaterials Congress
- L.H. Han, X.M. Tong, F. Yang. “Photocrosslinkable PEG-based Microribbons for Forming 3D Macroporous Scaffolds with Decoupled Niche Properties,”Advanced Materials,26, 1757-62, 2014.
- T.Y. Wang, J.H. Lai,L.H. Han, X.M. Tong, and F. Yang, “Chondrogenic differentiation of adipose-derived stromal cells in Combinatorial Hydrogels Containing Cartilage Matrix Proteins with Decoupled Mechanical Stiffnesses,”Tissue Engineering A, doi:10.1089/ten.tea.2013.0531, 2014.
- C.M. Madl, M. Keeney, X.L. Li,L.H. Han, and F. Yang, “Co-release of cells and polymeric nanoparticles from sacrificial microfibers enhances non-viral gene delivery inside 3D hydrogels,”Tissue Engineering C, doi:10.1089/ten.tec.2013.0669, 2014
- L.H. Han, S. Yu, T.Y. Wang, A.W. Behn, F. Yang, "Microribbon-like Elastomers for Fabricating Macroporous and Highly Flexible Scaffolds that Support Cell Proliferation in 3D,“Advanced Functional Materials,23, 346-58, 2013.
- M. Keeney, S. Onyiah, Z. Zhang, X. Tong,L.H. Han, F. Yang, “Modulating Polymer Chemistry to Enhance Non-viral Gene Delivery inside Hydrogels with Tunable Matrix Stiffness,”Biomaterials34, 9657-65, 2013.
- L.H. Han, J.H. Lai, S. Yu, F. Yang, “Dynamic Tissue Engineering Scaffolds with Stimuli-Responsive Macroporosity Formation,”Biomaterials,34, 4251-8, 2013.
- J. Hammer,L.H. Han, X.M. Tong, F. Yang, “A Facile Method to Fabricate Hydrogels with Microchannel-like Porosity for Tissue Engineering,”Tissue Engineering C,20, 169-76, 2013.
- M. Nii, J.H. Lai, M. Keeney,L.H. Han, A.W. Behn, G. Imanbayev, F. Yang, “The Effects of Interactive Mechanical and Biochemical Niche Signaling on Osteogenic Differentiation of Adipose-derived Stem Cells Using Combinatorial Hydrogels,”Acta Biomaterialia,9, 5475-83, 2012.
- D.Y. Fozdar, P. Soman, J.W. Lee,L.H. Han, S.C. Chen, "Three-dimensional Polymer Constructs Exhibiting a Tunable Negative Poisson's Ratio,"Advanced Functional Materials,21, 2712-20, 2011.
- L.H. Han, S.M. Wu, J.C. Condit, N.J. Nate, M.D. Feldman T. Milner, S.C. Chen, “Light-Powered Micromotor: Design, Fabrication, and Mathematical Modeling,”Journal of Microelectromechanical Systems,20, 487-96, 2011.
- S. Suri,L.H. Han, W. Zhang, A. Singh, S. Chen, and C.E. Schmidt, “Solid Freeform Fabrication of Designer Scaffolds of Hyaluronic Acid for Nerve Tissue Engineering,”Biomedical Microdevices,13, 983-993, 2011.
- L.H. Han, S.M. Wu, J.C. Condit, N.J. Nate, M.D. Feldman T. Milner, S.C. Chen, “Light-Powered Micromotor Driven by Geometry-Assisted, Asymmetric Photon-heating and Subsequent Gas Convection,”Applied Physics Letters,96, 213509 (1-3), 2010.
- L.H. Han, J.A. Easley, C.J. Ellison, S.C. Chen, “Fluorinated Colloidal Emulsion of Photo-changeable Rheological Behavior as a Sacrificial Agent to Fabricate Organic, 3D Microstructures,”Langmuir,26, 6108-10, 2010.
- L.H. Han, S. Suri, C. Schmidt, S.C. Chen, “Fabrication of three-dimensional Scaffold for Heterogeneous Tissue-engineering,”Biomedical Microdevices,12, 721, 2010.
- W. Zhang,L.H. Han, S.C. Chen, “Integrated Two-Photon Polymerization With Nanoimprinting for Direct Digital Nanomanufacturing,”Journal of Manufacturing Science and Engineering,132, 030907 (1-5), 2010.
- L.H. Han, W. Wang, Y. L. Lu, R. J. Knize, K. Reinhardt, J. R. Howell, S. C. Chen, "Analytical and Experimental Investigation of Electromagnetic Field Enhancement among Nanospheres with Varying Spacing,"Journal of Heat Transfer,131, 033110, 2009.
- S.M. Wu,L.H. Han, S. C. Chen, "Three Dimensional Selective Growth of Nanoparticles on a Polymer Microstructure,"Nanotechnology,20, 285312 (1-4), 2009.
- L.H. Han, G. Mapili, S.C. Chen, K. Roy, "Projection Micro-Printing of Three-Dimensional Scaffolds for Tissue Engineering,"Journal of Manufacturing Science and Engineering,130, 021005-1-4, 2008.
- K. C. Dickey, S. Subramanian, J. E. Anthony,L. H. Han, S.C. Chen, Y.L. Loo, "Large-area Patterning of A Solution-processable Organic Semiconductor to Reduce Parasitic Leakage and Off Currents in Thin-film Transistors,"Applied Physics Letters,90, 244103, 2007.
- L.H. Han, T.J. Tang, S.C. Chen, "Tuning the Absorption of Au Nanospheres on a Micro-Shell by Photo-Deformation,"Nanotechnology,17, 4600-5, 2006.
L.H. Han, S.C. Chen, "Wireless Bimorph Micro-actuators by Pulsed Laser Heating,"Sensors and Actuators A,121, 35-43, 2005.