WANG, Chi-Hwa

Professor

Department of Chemical and Biomolecular Engineering

National University of Singapore; 4 Engineering Drive 4, Singapore 117576
Tel: (65) 6516-5079

Group Website: Here

Education

Ph.D (Chemical Engineering), Princeton University, 1996
M.A (Chemical Engineering), Princeton University, 1993
M.S. (Biomedical Engineering), Johns Hopkins University, 1991
B.S. (Chemical Engineering), National Taiwan University, 1987

Work Experiences

National University of Singapore, Department of Chemical and Biomolecular Engineering Engineering, Lecturer (Assistant Professor), 1995- June 2003. Associate Professor July 1, 2003 – June 30, 2010. Professor July 1, 2010 – Present
National Taiwan University, Department of Chemical Engineering, Visiting Assistant Professor, September 1999 – January 2000,January – May 2002. Visiting Associate Professor, September 2005- January 2006.
Singapore-MIT Alliance, Fellow, 2001-2006.
Kyoto University, Department of Chemical Engineering , JSPS Visiting Fellow, May – June 2003.
Cambridge University, Department of Chemical Engineering , (Sabbatical) Visitor, April – July 2004.
Massachusetts Institute of Technology, Department of Chemical Engineering , (Sabbatical) Visting Associate Professor, July – September 2004.
National University of Singapore, Faculty of Engineering, Assistant Dean for Research, March 2006 – June 2008.
Member, Editorial Board, Powder Technology, Elsevier, 2008 –
Member, Editorial Board, Journal of Controlled Release, Elsevier, 2009 –
Executive Editor, Advanced Powder Technology, Elsevier, 2009 – 2012
Conference Chair, The 5th Asia Particle Technology Symposium, Singapore, 2012
Chair, Scientific and Technical Committee, Asia Pacific Confederation of Chemical Engineering Congress, Singapore, 2012
Executive Editor, Chemical Engineering Science, Elsevier, 2013 – 2022
Chair, The 15th International Conference on Sustainable Energy Technologies (SET2016), Singapore, July 2016
Chair, Frontiers in Chemical Engineering. The 8th Global Chinese Chemical Engineering Symposium (GCCES2016), Singapore 2016, July 2016.

Chair, E2S2 CREATE and AIChE Waste Management Conference, 11-13 March 2019, (https://www.aiche.org/ifs/conferences/e2s2-create-and-aiche-waste-management-conference/2019).

Chair, Fluidization XVI, Guilin, China, 26-31 May 2019 (jointly organized by AIChE and CSP (https://www.aiche.org/conferences/fluidization/2019).

Co-Chair, 3rd AIChE Sustainable Waste Management Conference, 4-6 August 2021, Virtual. (jointly organized by AIChE, E2S2 CREATE and APRU Sustainable Waste Management https://www.aiche.org/ifs/conferences/sustainable-waste-management-conference/2021).

Honors & Awards

Hoechst Celanese Excellence in Teaching Award, Princeton University, 1993.
Hoechst Celanese Excellence in Teaching Award, Princeton University, 1994.
E-Council Excellence in Teaching Award, Princeton University, 1995.
Charlotte Elizabeth Procter Honorific Award, Princeton University, 1995.
Teaching Honours List Award, Faculty of Engineering, National University of Singapore, 1997.
Teaching Honours List Award, Faculty of Engineering, National University of Singapore, 1998.
CrayQuest Gold Award, Jointly presented by the Silicon Graphics & Institute of High Performance Computing, Singapore, 1998.
Outstanding Paper Award, Society of Chemical Engineering Japan, 2000.
HPC Quest Silver Award, Jointly presented by IBM & Institute of High Performance Computing, 2004.
Teaching Commendation List, Faculty of Engineering, National University of Singapore, 2006.
Chemical Engineering Science Most Cited Paper 2003-2006 Award, Elsevier Publisher, 2007
Teaching Commendation List, Faculty of Engineering, National University of Singapore, 2007.
Runner-Up, Mimics Innovation Awards, Washington DC, USA, 2007.
Teaching Commendation List, Faculty of Engineering, National University of Singapore, 2008.
Teaching Commendation List, Faculty of Engineering, National University of Singapore, 2009.
Frontier Award, Fluid & Particle Processing Division, the Society of Chemical Engineers, Japan (SCEJ), 2012.
AIChE Shining Star Award 2016.
WSSET (World Society of Sustainable Energy Technologies), Award 2017, Bologna, Italy, July 2017.
AIChE Shell Thomas Baron Award, 2018, Pittsburgh, USA, November 2018.
Elected AIChE Fellow, August 2019. Elected WSSET Fellow, August 2020.

Elected WSSET Fellow, August 2020.

Clarivate Highly Cited Researcher 2023.

Research Interests

Waste to Energy and Resource: Gasification Technology (coal, biomass & municipal solid waste); Characterization and reuse of gasification bottom and fly ash.
Rheology of Granular Materials: Flows and Dynamics of Granular Materials; Flow Instabilities in Particulate Systems.
Biomedical Engineering: Tumor Drug Delivery Systems; Controlled Release Devices.

Professor Chi-Hwa Wang’s research has focused on developing a fundamental understanding of the generation and transport of electrostatics in in fluid-particle flow systems and applying this understanding to improve the flow measurements and characterization of chemical and pharmaceutical processes.

Waste to Energy

The Chi-Hwa Wang research group has developed new projects on translational research of particle technology particularly for renewable energy applications. Since 2012, his research group has focused on the co-gasification based clean energy production from carbonaceous solid waste using advanced particle simulation models and renewable energy technology (e.g. solar energy). Experimental and numerical studies of co-gasiﬁcation of woody biomass and sewage sludge have been carried out. The gasiﬁcation experiments were performed in a ﬁxed-bed downdraft gasiﬁer and the experimental results show that 20 wt % dried sewage sludge in the feedstock was effectively gasiﬁed to generate producer gas comprising over 30 vol % of syngas with an average lower heating value of 4.5 MJ/Nm³. Further increasing sewage sludge content to 33 wt % leads to the blockage of gasiﬁer, which is resulted from the formation of agglomerated ash. The numerical models were then developed to simulate the reactions taking place in four different zones of the gasiﬁer (i.e., drying, pyrolysis, combustion, and reduction zones) and to predict the producer gas composition and cold gas efﬁciency. The deviation between the numerical and experimental results obtained was lower than 10%. [ Ong, YP Cheng, T. Maneerung, Z. Yao, Y. Dai, Y.W. Tong, C.H. Wang, “Co-gasification of woody biomass and sewage sludge in a fixed-bed downdraft gasifier”, AIChE Journal, 61, 2508-2521 (2015).

Flows and Dynamics of Granular Materials

Through experiments and simulations, the characterization of electrostatics in pneumatic conveying, fluid-particle flows, and fluidized bed systems, have been investigated from a series of studies from year 2004 to 2017 by Chi-Hwa Wang’s research group, focusing on the following aspects, (1) measurement accuracy of electrical capacitance tomography under the influence of electrostatics, Chem. Eng. Sci., 59(15) 3201-3213(2004). (2) electrostatics of the granular flow in a pneumatic conveying system, Ind. Eng. Chem. Res., 43, 7181-7199 (2004). (3) effects of an electrostatic field in pneumatic conveying of granular materials through Inclined and vertical pipes, Chem. Eng. Sci. 61, 7889 – 7908 (2006). (4) on the electrostatic equilibrium of granular flow in pneumatic conveying systems, AIChE Journal, 52 (11) 3775-3793 (2006). (5) particle attrition due to rotary valve feeder in a pneumatic conveying system: electrostatics and mechanical characteristics, Canadian Journal of Chemical Engineering, 84, 663-679(2006). (6) hazard of electrostatic generation in pneumatic conveying system: electrostatic effects on the accuracy of electrical capacitance tomography measurements and generation of spark, Measurement Science and Technology, 19, 015502 (2008). (7) electrostatic characterization of electrohydrodynamic atomization process for polymeric particle fabrication, J. Aerosol Sci. 39, 987-1002(2008). (8) electrostatic characteristics in a large-scale triple-bed circulating fluidized bed system for coal gasification, Chem. Eng. Sci., 75, 435-444 (2012). (9) experimental and numerical investigations on the electrostatics generation and transport in the downer reactor of a triple-bed combined circulating fluidized bed, Ind. Eng. Chem. Res., 51, 14258-14267 (2012). (10) investigation on hydrodynamics of triple-bed combined circulating fluidized bed using electrostatic sensor and electrical capacitance tomography Ind. Eng. Chem. Res., 52(32) 11198-11207 (2013). (11) investigation on hydrodynamics of triple-bed combined circulating fluidized bed using electrostatic sensor and electrical capacitance tomography”, Ind. Eng. Chem. Res., 52(32) 11198-11207 (2013). (12) electrostatic charging and its effect on mixing of binary particles in a vibrating bed”, Ind. Eng. Chem. Res., 53, 14166-14174 (2014), (13) experimental investigations of granular shape effects on the generation of electrostatic charge, Particuology, 15, 82–89 (2014), (14) application of electrical capacitance tomography in particulate process measurement – A review”, Advanced Powder Technology, 25, 174-188 (2014). (15) investigation of granule electrostatic charge generation with normal stress effect”, Advanced Powder Technology, 27(5), 2094-2101 (2016), (16) investigation of granular surface roughness effect on electrostatic charge generation”, Advanced Powder Technology, 28(9), 2003-2014 (2017).

Drug Delivery Systems

With the advancement in medical science and understanding the importance of biodistribution and pharmacokinetics of therapeutic agents, modern drug delivery research strives to utilize novel materials and fabrication technologies for the preparation of robust drug delivery systems to combat acute and chronic diseases. Compared to traditional drug carriers, which could only control the release of the agents in a monotonic manner, the new drug carriers must be able to provide a precise control over the release time and the quantity of drug introduced into the patient’s body. To achieve this goal, Chi-Hwa Wang’s group introduced novel engineered particles with a core-shell micro-structure which could precisely tune the release rate for a definite time period. The proposed technology only utilized engineering approaches to shape the particles suitable for a particular purpose. Ideally, such particles could determine flexible release pattern and intensify the efficacy of a therapy via controlling time, duration, dosage, and location of drug release in a predictable, repeatable, and reliable manner. [P. Davoodi, F. Feng, Q. Xu, W.C. Yan, Y.W. Tong, M.P. Srinivasan, V. K. Sharma, C.H. Wang, “Coaxial Electrohydrodynamic Atomization: Microparticles for Drug Delivery Applications”, Journal of Controlled Release, 205, 70-82 (2015); P. Davoodi, W.C. Ng, W.C. Yan, M. P. Srinivasan, C.H. Wang, “Double-walled Microparticles-embedded Self-crosslinked, Injectable, and Anti-bacterial Hydrogel for Controlled Sustained Release of Chemotherapeutic Agents”, ACS Applied Materials & Interfaces, 8(35), 22785-22800 (2017)].
Besides working on the fundamental aspects of the particle formation, Chi-Hwa Wang has directed his research toward the translational applications of the particles in biomedicine. His group formulated several drug-loaded micro-/nano-particles precisely designed to release their cargos at specific target sites (inside a patient’s body) and combat diseased cells. In one of these projects, they utilized coaxial electrohydrodynamic atomization for the preparation of microspheres with distinct core/shell structures. This allowed the encapsulation of two drugs with different characteristics in hydrophilic properties in one single step. Variation of ratios between outer flow and inner flow produces polymer microspheres with different core/shell ratios, and consequently resulted in variable release rates of drugs. Significant changes in release patterns were demonstrated when the distributions of the two drugs in microspheres were swapped. Moreover, cell culture experiments and animal experiments have been carried out to testify the performances of different microspheres in cytotoxicity, cellular apoptosis in vitro and tumor growth inhibition. Moreover, the release rates and characteristic sequences of multi-drugs could be tailored and tuned according to treatment necessity and applied in treating other kinds of tumors. [H. Nie, Y. Fu, C.H. Wang, “Paclitaxel and suramin loaded core/shell microspheres in the treatment of brain tumors”, Biomaterials, 31, 8732-8740 (2010)].
Recently, Chi-Hwa Wang’s group has started adopting EHDA with 3D-printing technology and utilize the particle formation concept for the precise deposition of materials and cells. The precise deposition of the agents is of great interests as it directly affects the functions of a 3D-bioprinted tissue construct. They used their new technology to precisely deposit a reinforced skin extracellular matrix that supports cell proliferation and metabolism for over a week. Collagen was used as the main component of dermis-mimicking extracellular matrix, to which live primary human cells were added. The primary fibroblasts were seen to proliferate within the reinforced collagen matrix and expressed autologous ECM. This construct supported stratification and differentiation of skin primary cells, as confirmed by biomarker antibody immunohistochemistry. These results support the concept of future routine organotypic culture standardization through the combination of EHDA and 3D-bioprinting.

Collaborations

In the past 25 years, Dr. Chi-Hwa Wang collaborated with the following overseas research groups on various topics of particle technology ranging from fundamental studies for multiphase flow modelling and simulation, characterization, and process tomography to the biomedical and pharmaceutical applications of different particulate drug dosage forms: Professor John Bridgwater (Cambridge University, particle attritions); Professor Shuji Matsusaka (Kyoto University, electrostatics); Professor Jonathan Seville (University of Birmingham, PEPT); Professor Sankaran Sundaresan (Princeton University, pneumatic transport, electrical capacitance tomography); Professor Kenneth A. Smith (MIT, pharmaceutical particles and transport phenomena); Professor Ai-Bing Yu (University of New South Wales, DEM simulations); Professor Daniel W. Pack (University of Illinois @ Urbana Champaign, fabrication of core-shell microparticles); Professor Nick Sahinidis (Carnegie Mellon University, modeling and optimization of particulate foam for drug delivery); Professor J.C.M. Marijnissen (Delft University of Technology, EHDA); Professor William B. Krantz (University of Colorado, Boulder, scaling law for EHDA system); Professor A. Tsutsumi (University of Tokyo, coal gasification for clean energy studies); Professor W.Q. Yang (University of Manchester, electrical capacitance tomography); Professor Yanjun Dai & Tiansu Ge (Shanghai Jiaotong University, Waste conversion to energy and resources). Professor Wojciech Lipinski (Australia National University, Solar thermal conversion); Professor Yong Sik Ok (Korea University, Waste conversion to resources); Professor Daniel Tsang (Hong Kong Polytechnic University, Waste conversion to resources). Professor Eilhann E. Kwon (Sejong University, Waste conversion to resources); Professor Yong Shuai (Harbin Institute of Technology, Solar thermal conversion).

Interviews

- (1) 2017 Interview with AIChE. 2017 AIChE Annual Meeting, Minneapolis, USA https://www.youtube.com/watch?v=Mp3LiUNts1c&sns=em
- (2) 2016 Interview with NUS AIChE Student Chapter. https://www.youtube.com/watch?v=7hSzwxdAWUE&sns=em