Keynote Speakers
Biography: Bin Liu received BS degree from Nanjing University and Ph.D. degree from the National University of Singapore (NUS) before her postdoctoral training at the University of California, Santa Barbara. She joined the Chemical and Biomolecular Engineering Department of NUS in late 2005. She was promoted to Associate Professor in 2010 and was named as Chair Professor in 2014. Her current research focuses on organic nanomaterials for biomedical and energy applications. Dr. Liu has received many highly prestigious awards, including Singapore President’s Young Scientist Award 2008, L’Oréal Women in Science National Fellowship 2011, Asia Rising Star 2013, BASF Materials Award 2014, Materials in Society Lectureship 2015, Singapore President’s Technology Award 2016, and Asian Scientist Top 100 List in 2017. Dr. Liu was named as The World’s Most Influential Minds and the Top 1% Highly Cited Researchers in Materials Science by Thomson Reuters during 2014- 2017. Dr. Liu is the Fellow of Singapore Academy of Engineering, Asia-Pacific Academy of Materials, the Royal Society of Chemistry and serves as the Associate Editor for Polymer Chemistry.
Prof. Liu Bin, NUS. Provost's Chair, Department Head, Dept of Chem & Biomolecular Eng.
Topic:
Aggregation-Induced Emission: Materials and Biomedical Applications
Abstract: The recent years have witnessed the fast grow of fluorogens with aggregation-induced emission characteristics (AIEgens) in biomedical research. The weak emission of AIEgens as molecular species and their bright luminescence as nanoscopic aggregates distinguish them from conventional organic luminophores and inorganic nanoparticles, making them wonderful candidates for many high-tech applications. In this talk, we summarize our recent AIE work in the development of new fluorescent bioprobes for biosensing and imaging.[1,2] The simple design and fluorescence turn-on feature of the molecular AIE bioprobes offer direct visualization of specific analytes and biological processes in aqueous media with higher sensitivity and better accuracy than traditional fluorescence turn-off probes. The AIE dot probes with different formulations and surface functionalities show advanced features over quantum dots and small molecule dyes in noninvasive cancer cell detection, long term cell tracing, and vascular imaging.[3] In addition, our recent discovery that AIEgens with high brightness and efficient reactive oxygen species generation in aggregate state further expanded their applications to image-guided cancer surgery and therapy.
A/Prof Low Hong Yee, SUTD. Director of DmanD Centre.
Topic:
Progress in Biomimetic Micro and Nano-scale Surfaces: From 2D Substrate to 3D Objects
Biography: Hong Yee Low received her PhD from the Macromolecular Science and Engineering department of Case Western Reserve University in 1998. After spending 2 years at Motorola Semiconductor Sector, she spent 13 years at the Institute of Materials Research and Engineering, Agency for Science Technology and Research, Singapore. She is currently an associate professor in the Engineering Product Development Pillar at the Singapore University of Technology and Design and concurrently heading the Digital Manufacturing and Design (DmanD) center. Her primary research interest is in nanofabrication of functional surfaces.
Abstract: Functional, biomimetic or bioinspired micro and nano-scale surfaces have been achieved via either bottom up, top-down or combination processes, which are primarily lithographic-centric. A variety of functionalities such as surface wettability, friction and optical effects have been achieved through a variety of micro and nano-scale surface textures. Texturing surface with micro and nanoscale structures provide a non-chemical means to engineer surfaces without compromising the bulk material properties. The success of incorporating textured surfaces in product development depends greatly on the complexity of the product form factors and functions. Factors such as overall product performance, product form factor and material restrictions are some of the integration issues that must be overcome. An example is presented here for gecko-foot mimetic dry adhesive films and their integration into 2D and 3D products.
Gecko-foot mimetic surface structure has attracted a great deal of research interest for its potential as a chemical-free adhesive. Excellence progress has been achieved in the fabrication of high aspect ratio, often comprising hierarchical structure, dry-adhesive1. However, the successful application of these surfaces depends greatly on their integration into the application or product of interests. This presentation will highlight the challenges and the strategies to overcome the designs, fabrication and integration of gecko foot mimetic dry adhesive in potential products: surgical tape2 and climbing robots3,4 representing a 2D and 3D form respectively. Recent research results from a scalable direct fabrication of gecko-foot mimetic adhesive surface texture on 3D objects will be discussed.
Prof John Wang, NUS. Head of Dept of Mat’ls Sci & Eng.
Topic:
From MOFs to Active Materials for Energy Storage and Conversion
Biography: Professor Wang’s (Fellow, IoM3, UK, 2003, & Ph.D. (Ceramics), University of Leeds, UK, 1987) research focuses on new functional ceramics, electroceramic and composite materials that are inevitably required for the next generation of energy generation and storage, electronics and healthcare. His research group has been working on novel fabrication techniques for these materials and understanding of the correlations between their structural parameters, at various length scales ranging from molecular, nanometer to micrometer ranges, and their functional properties. More recently, Professor Wang’s research is concentrating on carbon-based materials, nanohybrids and mesoporous materials for energy generation, energy storage and biomedical applications. He and his research group have successfully developed several types of new nanohybrids and mesoporous materials for applications in energy generation storage and drug delivery.
Abstract: We have been exploring a class of MOF-derived active materials for both energy storage and conversion. These active materials can be grown into various 3D, 2D, 1D and 0D morphologies, together with great flexibility in control over varying length scales from atomic scale up to bulk structures, allowing for almost endless varieties. These MOF-derived active materials are exceptionally high performing in both energy storage and conversion, such as for both electrocatalysts and electrodes in batteries and supercapacitors. Several new compound-type active materials, including metal phosphides, nitrides, carbides, carbonitrides have been developed from MOFs in our labs more recently. They can be developed into various free-standing, nanohybids, or assembled on other active materials. This talk will present the current status of these MOF-derived active materials and conclude with a brief future perspective.
Prof Loh Kian Ping, NUS. Provost’s Chair Professor.
Topic:
Tailoring sample-wide pseudo-magnetic field in Graphene
Biography: Kian Ping Loh completed his Ph.D degree in Physical and Theoretical Chemistry, University of Oxford in 1996. He is currently the Provost’s Chair professor in the National University of Singapore and also the Head of 2D Materials Research in the Centre for Advanced 2D Materials. He is also the associate editor of the American Chemical Society journal Chemistry of Materials and serves on the international advisory board of journals such as Advanced Functional Materials, Materials Horizon and 2D Materials. His research interests are focused on 2D materials, which include graphene, 2-D polymer, 2-D perovskites and 2-D inorganic material. `His team was the first to demonstrate the use of atomic layer graphene as saturable absorber in mode-locked fiber laser for the generation of ultrashort soliton pulses (756 fs) at telecommunication band. In 2010, K. P. Loh’s team made another pioneering contribution to graphene photonics by demonstrating broadband optical polarization in graphene for the first time, the work is published in Nature Photonics. He developed a face-to-face transfer method for graphene on wafer in 2014 (Nature). K. P. Loh was conferred the President’s Science Award in Singapore in 2014 and the American Chemical Society’s ACS Nano Lecture award in 2013. He currently has a google Hirsch index of 83 and has received >35,000 citations for his publications.
Abstract: Strain-induced pseudo-magnetic fields (PMFs) in graphene have been explored as a promising approach to engineer the electronic states of graphene, producing intriguing physics such as valley polarized current. Many researchers have been attracted by the enormous pseudo- magnetic fields (up to 300T) observed in non-planar, strained graphene nanostructures such as graphene nanobubbles, but these are distributed randomly and remain an intellectual curiosity, and cannot be implemented practically in any electronic devices. In theory, it is predicted that strains with triangular symmetry is able to create pseudo-magnetic field, but currently there is no known experimental techniques to create the specific strain texture that can generate a uniform pseudo-magnetic field with the desired spatial distribution and intensity.
In a recent paper, we reported the observation of sample wide pseudo-magnetic fields on graphene by overlaying graphene on black phosphorous(BP) to form a G/BP heterostructure. The large lattice mismatch and shear strain imposed on both lattices give rise to a pseudo- magnetic fields via superlattice formations. We are able to tailor the intensity and spatial distribution of the pseudo-magnetic fields on graphene by simply changing the rotation angle between graphene and BP crystallographic directions. In the presence of external magnetic fields they observed a valley polarized current the signature of pseudo-magnetic fields, in transport measurement of field effect transistor (FET) device for the first time. These findings show a practical way ahead for achieving large area, uniform pseudo-magnetic fields, which can be employed in graphene-based valleytronics and pseudo-spintronics.
Finally, we show that graphene-BP heterostructure presents enticing prospects for making highly sensitive magnetoresistance (MR) device. Colossal MR was obtained from a vertical heterostructure constructed by stacking monolayer G on BP, with a local MR reaching ~775% at 9 T and 300 K. The average MR values of our 2D G/BP heterostructure are several times larger than that of conventional magnetic tunnelling junction (~220% at RT). MR measured in nonlocal geometry is ∼10 000% even at room temperature, which is 4 times higher than that for the G/h-BN device (∼2300−2600% at 9 T, 300 K) and 100 times larger than that observed for G/SiO2 (∼80−120% at 9 T, 300 K).
Dr Zhang Yong-wei, IHPC, A*STAR. Principal Scientist | Deputy Executive Director.
Topic:
An integral digital twin platform for powder-bed additive manufacturing: From powder to part
Biography: Dr. ZHANG Yong-Wei is Principal Scientist II and Deputy Executive Director at Institute of High Performance Computing (IHPC), A*STAR, Singapore. He received Ph.D from Northwestern Polytechnical University, China. Subsequently he worked at Institute of Mechanics, Chinese Academy of Sciences, China; Division of Engineering at Brown University, USA; Institute of Materials Research and Engineering, A*STAR, Singapore; and Department of Materials Science and Engineering at National University of Singapore. His research interests focus on using theory, modelling and computation as tools to study the relationship between structures and properties of materials with applications in materials design, materials processing and manufacturing, property engineering, mechanical-thermal coupling, mechanical-electronic coupling, and mechanical properties of biomaterials et al. He holds Adjunct Position at National University of Singapore and Singapore University of Technology and Design. He is Editorial Member for Advanced Theory and Simulation and International Journal of Applied Mechanics. He has published over 420 refereed journal papers, and delivered over 80 invited/keynote/plenary talks and lectures.
Abstract: Part property inconsistency and quality control are two major bottleneck issues in the current additive manufacturing (AM) technology. Computer simulation is a powerful tool to gain in-depth understanding into these bottleneck issues. We are developing an integrated digital twin platform for powder-bed selected laser melting (SLM) with aim to predict the printing outcomes, such as porosity, grain and phase microstructures, residual stress distribution and distortion, surface roughness and mechanical properties for given printing conditions. In this platform, a discrete element method is used to describe powder bed packing and levelling, a ray-tracking method is used to predict the laser energy adsorption, a combined lattice Boltzmann-phase field method is used to describe the melt pool dynamics, solidification process and solid phase transformation, and a homogenization method is used to estimate the mechanical properties. We have used IN718 super-alloy as a model material to test the predictability of the platform. Our simulation results show that the predictions are able to capture many interesting features of SLM processes. It is expected that the developed digital twin platform is of the potential to significantly promote the adoption of additive manufacturing technology by industry.
Prof Lee Pooi See, NTU, Assoc Dean, College of Engineering.
Topic:
Active perceptive stretchable materials and devices
Biography: Pooi See Lee is a Professor in the School of Materials Science and Engineering, Nanyang Technological University, Singapore. She received her Ph.D. from the National University of Singapore in 2002 in the field of semiconductor materials. She joined the School of Materials Science and Engineering at the Nanyang Technological University as an Assistant Professor in 2004. She became an Associate Professor with tenure in 2009 and Full Professor in 2015. Her research focuses on nanomaterials and hybrid composites for electronics, energy and human machine interface. She is the programme co-leader of the SHARE-NTU CREATE since 2012 and a lead investigator for the Competitive Research Programme awarded by the Singapore National Research Foundation in 2014. She won the National Research Foundation Investigatorship Award in 2015 and the Nanyang Research Award 2016. In 2018, she won the Nanyang Award for Innovation and Enterpreneurship. She holds more than 25 filed or granted patents and has authored 8 book chapters, with more than 250 publications in international reputable refereed journals. In addition, she received the National Day Award, Public Administration Medal (Bronze) in 2014 for her academic services. She is currently the Associate Dean (Faculty Recruitment and Development) in the College of Engineering in NTU.
Abstract: Sensory receptors help us learn the environment around us or decode our internal state. Stimuli from various sources cause the sensory cell to produce an action potential that gets integrated with other cognitive functions. Inspired by the realm of human physiology, we have constructed deformable devices using soft matter and hybrid composites that interpret strain, pressure, light, electrochemical and thermal changes. The emergence of stretchable and deformable devices inspired by free-form properties of artificial receptors can be proliferated to soft robotics, biomedical therapy or diagnostics and artificial intelligence.
To realize these domain of interests, our approach to fabricate flexible and stretchable devices have embraced extensive exploitation of active perceptive materials as building blocks. Electrical stretchable conductors have been prepared using composites of liquid metal and metallic nanomaterials with soft elastomers. For the active receptive surfaces, nanocoatings have been prepared with structural and chemical modifications of cellulosic materials that provide unique properties on versatile substrates. The modified nanocellulose based coatings on textiles present the ability to convert biomechanical motion into electrical output. We further demonstrate that by incorporating a charge trapping layer of 2D nanomaterials black phosphorus, the energy scavenger shows enhanced triboelectric energy output from contact mode. On the other hand, bionic like tactile and olfactory sensors with reversible stretchability can be realized using polymeric nanowire arrays on elastomer.
To further extend these strategies, nature-mimicking adaptive sensory and motor response systems can be artificially constructed with the exploitation of ionics. Ionic conductors were used to fabricate stretchable mechanical strain sensors while water controllable hydrochromics were realized to demonstrate optical modulation based on controlled fluid transport in soft matter. Advances in using ionic materials for electrochemical based devices has led to stretchable energy storage and electrochromics.
A/Prof Stefan Adams, NUS. Centre for Adv 2D Mat’ls | Dept of Mat’ls Sci & Eng.
Topic:
Hard and soft fast ion conductors enabling high energy density batteries
Biography: In my work, I combine in situ characterization by electrochemical, neutron and x-ray diffraction methods with computational approaches to promote the understanding of charge and mass transport in solids and the underlying structure-property correlations. Analyzing structural prerequisites for efficient transport opens a way for a systematic design of novel materials with tailored conductivities and stabilities for applications in energy storage, conversion and harvesting. While transport in the bulk of crystalline solids can essentially be well explained (though there are occasional surprises such as the “rock & roll” polyanion transport we found), novel experimental and theoretical approaches are required to promote the understanding of transport in nanoscopically heterogeneous and disordered systems.
The development of such new approaches constitutes a major focus of my work. To reach this goal, we employ (and advances the development of novel methods for) Molecular dynamics simulations and reverse Monte Carlo modelling, the combination of atomistic simulation with experimental structure information; simulation of interfaces and nanocrystalline particles, a novel energy landscape analysis for mobile ions in solids based on our bond softness-sensitive bond valence analysis, and develop effective force-fields for large-scale simulations.
Studies encompass a wide range of materials for sustainable energy applications such as fast ion conducting solids and mixed conducting cathode materials for lithium batteries with higher power or energy density, and ceramic fuel cells operating at moderate temperatures, nanocomposites for chemical and electrochemical energy storage, and tailored nanostructures for the harvesting of solar energy in dye- sensitized and organic bulk heterojunction solar cells.
Abstract: Electrolytes in current lithium and sodium-ion batteries are mostly based on mixtures of flammable liquid cyclic and linear organic carbonates leading to safety concerns especially during fast charging. The urgency to develop safer alternatives becomes the more imminent as the demand for higher density energy storage drives a transition to Li- or Na-metal based anodes that are incompatible with current electrolytes. Anode protecting membranes made of solid-state ionic conductors or the complete removal of flammable solvents in all solid state batteries appear as promising alternatives. The latter could also be operated safely over a much wider temperature range reducing the need for thermal management. Still this transition requires the identification of – at least kinetically – stable fast ionic conductors that can be processed at competitive cost and scale and are compatible with the other battery components.
Here we discuss new solid electrolytes that are capable to ensure a high rate performance based on the high mobility of alkali ions in various framework oxides and chalcogenides. Among the known sodium conducting electrolytes here we e.g. study the novel class of tetragonal Na3M1X4 –Na4M2X4 phases including the fastest Na-ion conducting sulfide Na11Sn2PS12,1 Na11.1Sn2.1P0.9Se12,2 solution-processable Na11Sn2SbS12, etc. with a redundant 3D pathway network and demonstrate their use in novel high energy density batteries.
Our redevelopment of the crystal chemical bond valence approach into our energy-scaled “bond valence site energy” (BVSE) method3 allows for computationally cheap predictions of ion migration pathways and migration barriers from static structure models and thus for high-throughput screening of wide ranges of candidate compounds as alkali ion or mixed conductors with balanced conductivity and stability. As the ionic conductivity in mixed conductors also controls the achievable rate performance of insertion electrode materials, we extended our combined ab initio and empirical bond valence analyses to alkali-ion electrode materials4,5 as well as to predicting electrolyte:electrode combinations with favourable interfacial properties.
Large-scale energy storage devices also place stringent demands on materials processability. Compared to brittle ceramics polymer composites enable easily scalable continuous production processes leading to tougher ultrathin membranes.6 Photopolymers as the polymer matrix allow for rapid curing and closer control on thicknesses compared to conventional solvent-evaporation casting and can be integrated more straightforwardly into additive manufacturing processes. Here, we present our investigation on the use of solid ionic conductor photopolymer composite membranes for Li-based battery applications.
Prof Sow Chorng Haur, NUS. Head of Dept of Physics.
Topic:
The Little Laser That Could
Biography: CH Sow received the B.Sc. degree (1st Hon) in Physics from the National University of Singapore (NUS) in 1991. After spending two more years in NUS, he received the M.Sc. degree in Physics from NUS. He went on to The University of Chicago and completed his PhD degree in 1998. During the period in 1999-2000, he worked as a Postdoctoral Fellow at Bell Laboratory, Lucent Technologies. He returned to NUS in year 2001. He is now a Professor with the Department of Physics. He has authored and coauthored a number of papers in the field of nanoscience and nanomaterials.
Abstract: Nanoscale materials have attracted great interests in recent years. Low dimensional systems such as 2D materials, nanoparticles, nanorods, nanowalls or networks are an important category of nanostructured materials with great potential as important components for nanoscale devices with various interesting functions. Thus, in the past decade, many techniques have been developed for the synthesis of such nanostructured materials. In addition, researchers have put in great effort in the studies of hybrid nanomaterials. With these efforts, a wide variety of nanostructured materials have been investigated. After the synthesis of the nanomaterials, it is desirable to be able to further modify the properties of the nanomaterials to improve the functionality of these nanomaterials. If we can create micropatterns on these as-grown nanomaterials, it will be able to further expand their potential applications. In recent years, efforts involve the alteration of physical and/or chemical properties of nanomaterials via the use of a focused laser beam have generated a lot of interests. In this presentation, we will present our efforts in the studies of hybrid nanomaterials with the emphasis on how the focused laser beam can be used as/for (a) Micro Manipulation Tool: Optical Tweezers, (b) Micropatterning and Microstructuring Tool, (c) Micro-Architecturing, (d) Micro-Photocurrent Studies, (e) Micro Photochemical Reaction (f) Micro light-House and (g) Micro-Actuating Tool.