Hongwei Zhu
Tsinghua University, China
Professor, Vice Dean of School of Materials Science and Engineering

Speech Title: Graphene-on-Surfaces for Multifunctional Applications
Abstract: Graphene has the potential for creating thin film devices, owing to its two-dimensionality and structural flatness. Assembling graphene-based building blocks into hybrid structures or composites with diverse targeted structures has attracted considerable interests for generating new properties and expanding its potential applications. The integration of graphene into a device always involves its interaction with supporting substrates, making this interaction critical to its real-life applications. This presentation will focus on three "graphene-on-surfaces" hybrid structures: I) graphene-on-semiconductor; II) graphene-on-polymer; III) graphene-on-ceramic.

Liqiu Wang
The University of Hong Kong, China
Professor, Qianren Scholar (Zhejiang), Director and the Chief Scientist for its Laboratory for Nanofluids and Thermal Engineering

Speech Title: Small is Big: Microfluidics-enabled Technology/Materials
Abstract: Droplets of nanoliter and subnanoliter are useful in a wide range of applications, particularly when their size is uniform and controllable. Examples include biochemistry, biomedical engineering, food industry, pharmaceuticals, and material sciences. One example of their many fundamental medical applications is the therapeutic delivery system for delivering site-specific therapy to targeted organs in the body and as the carriers for newer therapeutic options. The size, the size distribution, the generation rate and the effective manipulation of droplets at a scale of nano, pico, femto and even atto liters are critical in all these applications. This lecture contains two parts: an overview of microfluidic droplet generation/manipulation and microfluidics-droplet-enabled innovative technology/materials. The review of passive approaches focuses on the characteristics and mechanisms of breakup modes of droplet generation occurring in microfluidic cross-flow, co-flow, flow-focusing, and step emulsification configurations. The review of active approaches covers the state-of-the-art techniques employing either external forces from electrical, magnetic and centrifugal fields or methods of modifying intrinsic properties of flows or fluids such as velocity, viscosity, interfacial tension, channel wettability, and fluid density, with a focus on their implementations and actuation mechanisms. The microfluidics-droplet-enabled innovative technology/materials include smart surfaces for micro/nano-droplet manipulation, spider-web-like microfibers, liquid-repellent surfaces, super thermal conductor, automatic generator of microfluidic embolic microparticles, artificial blood vessels and 3D microfluidic bio-printing.

Jinliang He
Tsinghua University, China
Professor, Cheung-Kong Scholar Distinguished Professor of the Ministry of Education (China), Director of High-voltage and Insulation Technology

Speech Title: Smart Polymeric Composite for Self-adaptively Controlling Electrical Fields
Abstract: coming soon

Jiadao Wang
Tsinghua University, China
Chair Professor of Cheung Kong Scholar, Associate Director of Mechanical Engineering Department

Speech Title: Self-assembly of nano colloid particles for functional surface coatings and its applications
Abstract: Self-assembly of nano-colloid particles is a phenomenon where nano particles in a colloid assemble themselves to form a larger 2D or 3D functional structure, which can lead to a wide variety of materials that can be used for different purposes. We have developed some methods of self-assembly for 2D surface coatings. They include a self-assembly method based on repulsive electrostatic interactions between nanoparticles and a surface, and another one induced by a tension gradient near an interface. After self-assembly of nano-colloid particles, the thermodynamic molecular self-assembly of chain-like molecules of polytetrafluoroethylene was further developed for fabrication of a nano-fiber coating, and the thermodynamic self-assembly of metal nanoparticles such as gold below the melting point driven by surface thermodynamic fluctuations and atomic interaction forces in a nano-colloidal particle coating were found and analyzed. Using self-assembly techniques, surface coatings of filter materials with different wetting properties were prepared. Two methods of oil-water separation based on adjusted surface wettability of filters were presented. One is oil-penetration through a superhydrophobic filter, and another is water-penetration through a superoleophobic filter underwater.

You Wang
Harbin Institute of Technology, China
Professor, President of Surface Engineering Society of Heilongjiang province

Speech Title: Advanced materials for additive manufacturing
Abstract: Additive manufacturing (AM), especially known as 3D printing, depends on materials. If we do not have the appropriate materials, it can only be making bricks without straw even with the advanced 3D printer. Therefore, the main development direction of additive manufacturing, such as 3D printing, is using new special consumables materials. 3D printing is relatively easy to metals and difficult to high strength alloys, 3D printing is relatively more difficult to some ceramics, and may be harder to the nano ceramics. Nano-modification and nanostructured spherical particles powder makes it possible for the preparation of high strength alloy materials even nano ceramic materials through 3D printing.

Seung Hwan Ko
Seoul National University, Korea
Professor

Speech Title: Transparent & flexible/stretchable electronics fabrication by laser based nanomaterial processing
Abstract: It is well expected that the future electronics will be in the form of “wearable electronics”. Google’s Smart Glass and Apple’s iWatch are the first generations of wearable electronics. However, they are still mainly composed of rigid electronics even though human body is soft and elastic. To realize more meaningful and practical wearable electronics, electronic components should be stretchable or at least flexible. And “transparency” will add more functionality to the wearable electronics. We developed various (1) hierarchical multiscale hybrid nanocomposite for highly stretchable, highly flexible or highly transparent conductors, (2) laser based low temperature direct patterning processes alternative to conventional photolithography and vacuum deposition method and (3) large scale nanomaterial synthesis methods that ultimately can be applied for wearable electronics applications. The hybrid nanocomposite combine the enhanced mechanical compliance, electrical conductivity and optical transparency and the enhanced electrical conductivity to provide efficient multiscale electron transport path. Additionally, this approach combine “materials that stretch” and “structure that stretch” strategies to demonstrate highly stretchable conductor. Various demonstration along with process and material development in our lab will be introduced.

Sam Zhang
Southwest University, China
Professor, Expert of National Thousand Talents program, Director of new film materials and devices research center

Speech Title:Strategy to selection of additives for high performance double-cation mixed halide perovskite photovoltaics
Abstract:Composition design proved to be a promising approach in perovskite solar cells as is demonstrated recently with incorporation of Cs and Rb cations in double cation mixed halide perovskites system [(MAPbBr3)0.15(FAPbI3)0.85]. However, the role of the cation additives is still unclear, and the effect of anion addition remains mystery. In this work we investigated the role of different additives including group I alkali metal cations (K+, Rb+, Cs+ and NH4+) and halide anions (Br- and I-) on double-cation perovskites. A notably longer carrier lifetime is achieved in the perovskite films with addition of additives owing to the cation/anion defect passivation in the perovskite matrix. A selection rule is put forward based on the effect of the additive ionic size on structure stabilization and defect passivation. Under the guidance of this selection rule, NH4I is selected as additive to fabrication of a variety of devices. The performance improvement of these devices well matches the prediction. This shines light on the vast flexibility and possibility of perovskite composition design for high performance photovoltaics and LED applications.

Long Yu
South China University of Technology, China
Professor, Director of Sino-Singapore International Joint Research Institute

Speech Title:Biodegradable and Edible Starch-based Composites
Abstract:The aim of this work is to develop biodegradable and edible starch-based materials, in particular to reinforce the starch-based materials using biodegradable and edible agents, such as cellulous or starch crystals or self-reinforce techniques. The starch-based materials reinforced with natural fibres and cellulous or starch particles have been developed to various environmentally friendly composites. The hydrophilic properties of starch provide the advantage of compatibility with these nature fillers. Starch crystals, both micro- or nano- size, can be used as reinforce elements to improve the mechanical properties of starch-based materials. As expected, there are good interface between matrix and reinforce agent since chemically they have same structure.

Joshua Yang
University of Massachusetts, USA
Professor

Speech Title: Memristive materials and applications
Abstract: Memristive materials have become a promising candidate for next generation information techonology. In this talk, I will present some of our recent work on unconventional computing experimentally implemented by using memristive materials or device arrays.Using traditional non-volatile memristors with 64 stable analog resistance levels, we have built a dot-product engine based on a 128 x 64 1T1R crossbar array. Accurate image compression and filtering have been demonstrated with such analog computing accelerator3. In addition, we have demonstrated efficient and self-adaptive in-situ learning in a two-layer neural networks using such memristive arrays, which is expected to significantly improve the speed and energy efficiency of deep neural networks. Using our newly developed diffusive memristors with diffusion dynamics that is critical for neuromorphic functions, we have developed artificial synapses and neurons to more faithfully emulate their bio-counterparts and more efficiently perform spiking neural network functions. We have further integrated these artificial synapses and neurons into a small neural network, with which pattern classification and unsupervised learning have been demonstrated. Moreover, the diffusive memristors can be used as true random number generators for cybersecurity applications and artificial nociceptors for robotics applications.

Xiaorong Luo
University of Electronic Science and Technology of China, China
Professor, New Century Excellent Talents in University in China

Speech Title: An overview on the development of low power loss IGBTs
Abstract: Insulated Gate Bipolar Transistor (IGBT) is applied in a higher-voltage / higher power level than MOSFET because its conductivity modulation makes the forward voltage drop (Von) almost independent of doping concentration of drift region. Nevertheless, reducing the power loss and increasing the switching speed are still the research focus for IGBTs. This paper details typical techniques to reduce the power loss of IGBTs, covering anode engineering, injection enhancement and super junction. The anode engineering techniques accelerate the switching-off speed so as to decrease the Eoff, such as the shorted-anode structure, well-designed buffer layer and additional anode control-gate. The injection enhancement methods can reduce Von and conduction loss by enhancing the carrier concentration at cathode side without increasing the Eoff, including the carrier stored layer and narrow mesa region. The super junction approach features a secondary dimension expansion of depletion region, which also speeds up the sweep of excess carriers stored in drift region during the turn-off process. All these methods reduce the power loss and raise the switching frequency. On the other hand, the Si-IGBTs will face challenges in competition against its successor of SiC-IGBT, especially in the higher-power and higher-voltage applications.

Zhou Li
Beijing Institute of Nanoenergy and Nanosystems, CAS, China
Professor, Director of National center of nano science and technology

Speech Title:Self-powered Medical Electronic Devices
Abstract: Recently, piezoelectric nanogenerator(PENG) and triboelectric nanogenerator (TENG) have attracted much attention and been considered as another potential solution for harvesting mechanical energy. With its high output performance, outstanding biocompatibility and low cost, nanogenerator(NG) has been studied for powering implantable medical electronic devices. Here, we demonstrated an in vivo biomechanical-energy harvesting using a NG. An implantable triboelectric nanogenerator (iTENG) in a living animal has been developed to harvest energy from its periodic breathing. The energy generated from breathing and body moving was used to power a prototype pacemaker and a low-level laser cure (SPLC) system, respectively. It was found that the self-powered system could regulate the heart rate of a rat and significantly accelerated the mouse embryonic osteoblasts' proliferation and differentiation. Real-time acquisition and wireless transmission of self-powered cardiac monitoring data was demonstrated for the first time. It showed broad clinical applications of implantable self-powered medical systems for disease detection and health care. These works are concentrated on live-powered implantable medical devices. The NGs can convert the mechanical energy from human motion into electricity and drive the implanted long-term self-powered medical devices or biosensors. These are significant progress for fabricating implantable self-powered medical electronic devices using NGs as a power source and an active sensor.

Xiaoying Wang
South China University of Technology, China
Professor, New Century Excellent Talents in University in China

Speech Title: Chitosan-based 2D nanocomposite: Green fabrication and Bioapplications
Abstract: Two-dimensional (2D) nanomaterials have found widely application due to its high specific surface area. However, such materials suffer from aggregation and non-compatiablity to macromolecules matrix. Stabilizing agents are conventionally used to meet such chanlleges for 2D nanomaterial applications. Traditional stabilizing agents for 2D nanomaterials suffer from drawbacks such as toxicity, environmental pollution and negative effects on material performance, which limit the processing of 2D nanomaterial and its biomedical application. Thereforce, a major chanllege for 2D nanomaterial industrial application is to develop a green and environment friendly method for facile and efficient 2D nanomaterials preparation.
Chitosan is a green, environment friendly and biocompatible natural macromolecule bearing large amounts of hydroxyl and amino groups, which is a desired reducing and stabilizing agent for 2D nanomaterials. In our work, chitosan-based graphene nanocomposites were synthesized by cation exchanges and electrostatic self-assembly. Novel techniques and methods were set up for fabrication of chitosan-based 2D functional nanocomposite. Moreover, it is found that the exfoliation of two-dimensional (2-D) layered materials and the green synthesis of nano metal (gold and silver nanoparticles) in chitosan solution could be conducted simultaneously, during which a novel nano metal loaded chitosan-based 2-D layered composite was obtained. Such a composite was proved to show photothermal effects, and capabilities of DNA adsorption and bacterial detection. Application of such chitosan-based 2D nanocomposite as drug/gene carriers, adsorptive sponge, and polyelectrolyte hydrogels were explored.
In summary, these chitosan-based inorganic hybrid materials are showing extensive prospects for use in biomedical areas.

Meicheng Li
North China Electric Power University, China
Professor, Director of New Energy Materials and PV Technology Center, Associate Dean of the School of Renewable Energy

Speech Title: Interfacial Modification and Structure Design of the Novel Hybrid Solar Cells
Abstract: Surface modification is a practical approach to reduce carrier recombination at the surface and subsurface of the perovskite films caused by the trap states and the intrinsic nature of polycrystalline organometallic perovskites. Herein, an F4TCNQ interfacial layer is introduced, which possess dual function, i.e., surface passivation and interfacial doping of the perovskite. The perovskite solar cells (PSCs) with the dual function interfacial layer exhibit remarkable improvement in device performance and show enhanced long-term stability in ambient air without device encapsulation.
The structure of the perovskite solar cells is another critical factor influencing the device performance of perovskite solar cells. We present a novel structure for highly-efficient and stable PSCs, i.e., the embedded structure, which utilizes TiO2 nanoparticles embedded perovskite film as the absorption layer. The presence of TiO2 nanoparticles in perovskite film could improve the electron extraction, and promote the formation of a compact perovskite layer with large grains. The performance of the PSCs is significantly improved with the efficiency increasing from 16.6% for planar structure to 19.2% for the embedded structure. Furthermore, the TiO2 embedded PSCs, which have no any other chemical modifications, show excellent stability with efficiency keeping approach 80% (for average) or 90% (for the best) after being exposed in air for 28 days without encapsulation. Meanwhile, based on the interface modification, there are still other structure designs being carried out.