bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemical Decontamination Process an Effective Alternative to Treat Textile Effluents
Authors: Hussain Sajjad , Rehman Gohar Abdur , Ali Khan Abbas , Bilal Muhammad , Ahmad Qazi
Published: February 2020

Keeping in view the growing concern regarding aquatic pollution by effluent water from textile industries containing complex compounds, the present study was under taken with the view to study the efficiency of the removal by electrochemical oxidation. In recent year the use of electrochemistry for the investigation of environmental pollution is being thoroughly investigated. Reactive dye mainly composed of complex organic molecules are highly stable to decomposition in normal condition. Textile industry wastewater containing dyes poses a chronic and synergistic effects to environment. This study examines the electrochemical oxidation of the organic dyes. All the experiments were performed using a Filter Press Flow Cell Reactor containing Ti/Ti0.7Ru0.3O2 anode and stainless steel as cathode in which impact of the current density (5 – 20 mA cm-2), electrolytes (NaCl, Na2SO4, H2SO4), Sodium chloride concentration (0.02 – 0.10 mol L-1) were studied. The electrode used were characterized by the cyclic voltammetry experiments. The Reaction Kinetics and energy consumption parameters were studied of the electrochemical process. Results obtained in this research clearly demonstrated that the effect of the electro generated strong oxidant species active chlorine, depends on electro catalytic mechanism followed on surface of Ti/Ti0.7Ru0.3O2 resulting in the improvement of the color. Results also confirmed a high removal efficiency according to environment and electrolyte used in the process. However, there is a limit of NaCl for treating real effluents avoiding the formation of organochloride compounds; and it is a subject of critical importance, from the environmental point of view, to apply this alternative treatment.

Keyword: textile effluents, contaminants, electrochemical process, Kinetics
(Invited) Experimentally and Theoretically Determining Reaction Pathways for the Alkaline Hydrogen Electrode and Their Implications on Catalyst Design
Authors: Tang Maureen Han-Mei , Snyder Joshua David , Intikhab Saad
Published: February 2020

Even though hydrogen electrocatalysis has been studied for almost a century, it remains to be explained why higher pH slows the hydrogen evolution and oxidation reactions (HER/HOR) by a factor of 200, even on platinum [1]. This lack of understanding has serious implications not only for industrial electrolysis and next-generation energy storage, but for all electrocatalytic reactions in which pH may play a role. In this work, we investigate possible explanations for the effect of pH by combining microkinetic modeling with traditional electroanalytical methods. We specifically determine the viability of the proposed `bifunctional mechanism’, in which slow water dissociation is overcome by mediation of adsorbed hydroxide [2].

Our calculations [3] show that either a direct (hydroxide-as-spectator) or indirect (hydroxide-mediated) Volmer step can describe the reaction thermodynamics as revealed by slow-scan experimental cyclic voltammetry, but that only the direct Volmer step yields adsorption values consistent with literature. Modulating hydroxide adsorption strength via the electrolyte cation provides additional support for the direct mechanism. Experimentally, stronger hydroxide binding decreases kinetics, as observed by the dependence of peak-potential splitting on scan rate. Comparison with the model shows that this observation is consistent only with the direct mechanism.

Altogether, these results strongly suggest that adsorbed hydroxide serves as a competitive spectator in the alkaline Volmer step, and that the bifunctional HOR/HER mechanism plays only a minor role at best. This study contributes to resolving a long-standing paradox in electrocatalysis and surface science by determining that oxophilicity is not an accurate descriptor for alkaline hydrogen electrocatalysts. Other parameters, such as water orientation and non-covalent interactions, must play a greater role in overall activity. Efforts to identify and measure these parameters are ongoing.

[1] Durst et al. Energy Environ. Sci. 2014, 2255.

[2] Li et al. Angew. Chem. Int. Ed. 2017, in press.

[3] Intikhab et al, ACS Catal., 2017, in press.
(Invited) Superconducting Qubits and Superconducting Digital Electronic Circuits on 300mm Wafers
Authors: Papa Rao Satyavolu S. , Hobbs Christopher , Olson Stephen , Forouzani Neda , Chong Hyuncher , Stamper Harlan , Martinick Brian , Ashworth Dominic , Kaushik Vidya , Dunn Kathleen A , Beckmann Karsten , Nalaskowski Jakub , Bennett Stephen , Rodgers Martin , Murray Thomas , Novak Steven , Baker-O'Neal Brett , Borst Christopher , Osborn Kevin , Liehr Michael
Published: February 2020

Superconducting qubits have made great strides over the past decade, as evidenced by the announcement of 17-qubit and 50-qubit chips towards the end of 2017. The promise of quantum computing for solving problems of interest to society (such as complex drug design, and cryptography for national security, etc.) can be significantly advanced by the fabrication of qubits with high performance characteristics that faithfully replicate the designer's intent. Additionally, energy-efficient ways with low latency to control qubits at millikelvin temperatures are being researched. Superconducting digital electronics are one such approach, which can be 3D-integrated with qubits, with appropriate care taken to avoid quasi-particle poisoning of qubits.

In this presentation, the potential advantages and challenges of qubit and superconducting electronics fabrication using advanced 300mm wafer processes will be discussed, followed by a review of millikelvin characterization results from qubits fabricated using 193nm lithographic techniques on 300mm wafers. The selection of materials, and formation of high quality interfaces during the fabrication of superconducting structures will be discussed, along with high resolution transmission electron microscopy and other analyses that guide such process development – these serve to illustrate the potential for achieving further increases in coherence time and qubit frequency control through the use of advanced 300mm fabrication and characterization techniques.

The development of ‘manufacturing-friendly’ qubit architectures is essential to enable the creation of well-controlled qubits, as would be required to tackle practical computational problems of interest. Some of the approaches to ‘manufacturing-friendly’ qubit fabrication under consideration at SUNY Poly will be discussed, along with their 3D integration with control circuits and readout mechanisms.
Enhanced Non-Linearity Factor in Ferroelectric Tunnel Junction Based on HfO2 Heterojunction
Authors: Lee Joonbong , Lee Ho Jin , Choi Taekjib
Published: February 2020

Ferroelectric polarization, related to charge conduction, has shown some intriguing properties in ferroelectric tunnel junction as it has higher on/off ratio, lower power consumption and shorter process time. Conventional ferroelectrics have various problems when it is based on perovskite structure material, such as poor Si-compatibility, lead pollution and small energy bandgap. Recently, both ferroelectricity and anti-ferroelectricity have been reported in doped HfO2 thin film (<30 nm). The ferroelectricity and anti-ferroelectricity HfO2 thin films can be extremely thin with good Si-compatibility and large bandgap (>5 eV). Anti-ferroelectric/ferroelectric HfO2 heterojunction can enhance fatigue property and non-linearity of single ferroelectric tunnel junction. The space charge can be induced due to the stress in ferroelectric layer or ferroelectric/metal interface in 90° domain switching while anti-ferroelectric lowers the stress in the 180° domain switching. The HfO2 heterojunction can have non-linearity as it has higher resistance state under the threshold voltage for polarization switching. This structure with good fatigue property and non-linearity factor would contribute to the enhancement of ferroelectric tunnel junction memory device. This research was supported by the MOTIE (Ministry of Trade, Industry & Energy (#10080643) and KSRC (Korea Semiconductor Research Consortium) support program for the development of the future semiconductor device.
(Invited) GaN Sensors and Electronics for Missions to Hot Planets
Authors: Rais-Zadeh Mina
Published: February 2020

Hot planets or planets having harsh environments (e.g. Mercury and Venus) are abundant in the solar system. Specifically, Venus is a hot planet with a world similar to earth and exploring how climate and geology work on Venus could potentially provide a deeper understanding of the processes at work in our own environment. As such, there is an increasing interest in exploring such hot planets; but so far, the missions to these extreme environments have been very limited in scope and duration mainly due to unavailability of sensors and readout electronics that can survive the extreme environments of the planet . Recently, researchers have developed robust electronic devices and circuits that are resilient under the harsh space conditions. For example, ceramic semiconductor materials, such as gallium nitride (GaN) and silicon carbide (SiC) have been used to create space-grade microelectronics taking advantage of their temperature-tolerance, radiation-hardness and chemical stability. In the GaN material family, research into AlGaN/GaN heterostructures with high temperature capabilities has been ongoing for several decades. More recently, researches have shown that InAlN/GaN devices are operational up to 1000°C in vacuum. While there are compelling reports on the operation of electronics and circuits that sustain high temperature operation, there has not been much effort in developing sensors that can support scientific missions to hot planets. In this talk, I will go over new sensors and microsystems in GaN that can be monolithically integrated with either InAlN/GaN or AlGaN/GaN electronics to take various measurements including infrared, magnetic, and seismic, and thus enable long-lasting missions to hot planets with unprecedented science return.
(Invited) GaN-on-Diamond RF Transistors: The Next Generation Electronics
Authors: Kuball Martin , Pomeroy James W , Uren Mike
Published: February 2020

Current GaN-on-SiC RF electronic devices, although they already deliver outstanding performances are limited in power density mainly by the SiC substrate thermal conductivity. Integration of GaN with the highest thermal conductivity material known to mankind, diamond, offers the potential to increase power density in GaN devices by at least a factor of 5. State-of-the-art and current challenges will be discussed.
(Invited) High Performance β-Ga2O3 Nano-Membrane Field-Effect Transistors on Sapphire Substrate with Reduced Self-Heating Effect
Authors: Zhou Hong , Maize Kerry , Noh Jinhyun , Shakouri Ali , Ye Peide D
Published: February 2020

As a newly emerged semiconductor, β-Ga2O3 has an ultra-wide bandgap (Eg) of 4.8 eV and corresponding empirical high electrical breakdown field (Ebr) of 8 MV/cm as well as 300 cm2/V·s room temperature (RT) mobility (μ), which is identified as the next generation semiconductor to replace GaN and SiC. However, β-Ga2O3 field-effect transistors (FETs) on its native substrates suffer from severe self-heating effect due to its low thermal conductivity of 10~25 W/m·K. One approach to minimize self-heating effect is introducing β-Ga2O3 on insulator (GOOI) FET structure by replacing β-Ga2O3 native substrate with a higher κ and wider Eg substrate through wafer bonding technique. Here, we demonstrate that by utilizing a higher thermal conductivity sapphire substrate rather than SiO2/Si substrate, the temperature rise above room temperature of β-Ga2O3 GOOI FET can be reduced by a factor of 3 and thereby the self-heating effect is significantly reduced. Both thermo-reflectance characterization and simulation verify that the thermal resistance on sapphire substrate is less than 1/3 of that on SiO2/Si substrate. Therefore, maximum drain current density of 535 mA/mm is achieved on sapphire substrate, which is 70% higher than that on SiO2/Si substrate, due to reduced self-heating. Integration of β-Ga2O3 channel on a higher thermal conductivity substrate opens a new route to address the low thermal conductivity issue of β-Ga2O3 for power electronics applications.
Solid and Liquid State Fluorescent Sensor Using CdTe Quantum Dots for Mercury Detection
Authors: Choudhary Yogesh , Nageswaran Gomathi
Published: February 2020

Fluorescence based sensors are attractive owing to its ultra-sensitivity and ability to detect the analyte of interest with high specificity. Many metal ions although play vital role in ample number of biological events, few are highly toxic and even fatal.1
,
2 Hence, the field of metal ion detection using fluorescence spectroscopic technique has received tremendous attention in recent years.3 Among the fluorophores used for the metal ion detection, semiconductor based quantum dots such as CdTe, CdSe and CdS quantum dots have been exploited extensively for sensor applications on account of their bright and tuneable luminescence and ease of preparation.4
,
5

The present report focuses on the fluorescence based detection of Hg2+ ions using green-yellow emitting CdTe quantum dots, which perform as both signalling and analyte specific material. A complete characterization of CdTe quantum dots and CdTe-Hg2+ is carried out to confirm the formation of quantum dots and to understand the quenching mechanism. Here the emission of quantum dots is quenched by the addition of Hg2+, hypothesized to be due to the electron transfer mechanism. The sensor responds to Hg2+ in the linear range of 12 to 40 μM with a limit of detection 2 μM. Further, an easy visual detection strategy for Hg2+ is also established by dropcasting CdTe quantum dots over a glass plate.

References:

N. J. Langford and R. E. Ferner, J. Hum. Hypertens., 13, 651–656 (1999).

K. E. Giller, E. Witter, and S. P. Mcgrath, Soil Biol. Biochem., 30, 1389–1414 (1998).

S. Sahana and P. K. Bharadwaj, Inorganica Chim. Acta, 417, 109–141 (2014).

L. Zou, Z. Gu, and M. Sun, Toxicol. Environ. Chem., 97, 477–490 (2015).

M. Koneswaran and R. Narayanaswamy, Sensors Actuators, B Chem., 139, 91–96 (2009).
Ultraviolet Sensor Performance of Nanostructured LaCoO3 Prepared By Solution-Polymerization Method
Authors: Michel Carlos R , Lopez-Alvarez Miguel Angel , Martinez Alma H , Rodriguez Garcia Carlos Alberto
Published: February 2020

LaCoO3 has been extensively studied for their outstanding physical and chemical properties, which have applications in fields like heterogeneous catalysis, solid oxide fuel cells (SOFC’s), gas permeation membranes and gas sensors, to name a few [1,2]. LaCoO3 is a p-type semiconductor material, possessing the perovskite-type structure and has a band gap of 2.2 eV [3]. In this work, the detection of ultraviolet light (UV), as well as other light sources of different wave lengths (λ), was investigated for this oxide. For this purpose, polycrystalline LaCoO3 was synthesized by the solution-polymerization method, using an aqueous solution containing La and Co nitrates and polyvinyl alcohol. The identification of single-phase LaCoO3 was made by X-ray powder diffraction on samples calcined at 700ºC, in air. The surface microstructure was observed by field emission scanning electron microscopy, showing abundant porous sheets formed by networks of interconnected nanoparticles. Images obtained by transmission electron microscopy indicate that LaCoO3 crystallites have an average size of 50 nm. Measurements for detecting UV and light in the visible region were done at room temperature, using light emitting diodes (LEDs) of different λ and optical irradiances (Ee). The latter were done on LaCoO3 thick films prepared by depositing a suspension of the as-prepared powder on alumina substrates, with silver wires as electrodes. A typical graph showing the variation of the electrical resistance (R) with time, caused by the exposure of LaCoO3 to UV radiation (λ = 365 nm, Ee = 217 mW/cm2) and darkness, can be observed in Fig. 1. The results show a uniform response pattern, characterized by a decrease of resistance under UV light. The quantitative detection of UV radiation was also evaluated by varying the optical irradiance from 22 to 217 mW/cm2. The results indicate a non linear relationship between R and Ee, tending to a constant value while increasing Ee. I–V curves were also performed on LaCoO3 films confirming the latter results. For other light sources such as blue (λ = 449 nm), red (642 nm) and infrared (843 nm) reliable responses were also observed, noting that the change of R decreased by increasing λ. The results indicate that nanostructured LaCoO3 can be used as a wearable detector for UV radiation and a as sensitive material for photocells, among others. Even though this work was focused on UV detection, a good performance using light of larger λ was observed.

References

[1] Y. Wang, J. Ren, Y. Wang, F. Zhang, X. Liu, Y. Guo, G. Lu J. Phys. Chem. C 112 (2008) 15293.

[2] M. Ghasdi, H. Alamdari, Sens. Actuat. B 148 (2010) 478.

[3] S. Mukhopadhyay, M.W. Finnis, N.M. Harrison, Phys. Rev. B 87 (2013) 125132.

Figure 1
Light-Bias Duel Modulation on Spin-Coated Zinc-Tin Oxide (ZTO) Thin Film Transistor
Authors: Chen Jen-Sue
Published: February 2020

Zinc tin oxide (ZTO) is a transparent semiconductor based on earth-abundant elements. In this work, ZTO films prepared by spin coating via a solution route have been applied as the active semiconductor layer in a thin film transistor (TFT) with SiO2 dielectrics and Si gate. With thickness less than 10 nm, the ZTO film exhibits a good field-effect mobility of ~10 cm2/Vs, small subthreshold slope of ~0.5 V/decade and high on/off current ratio of ~107.

Under light illumination of 405 nm wavelength (below ZTO bandgap), the photoresponse of ZTO TFT is related to the ionization of neutral oxygen vacancies to positively-charged oxygen vacancies, which simultaneously produce photogenerated electron carriers. With power density upto 1 mW/cm2, the light sensitivity is in the order of 105~106 for the ID-off region. The light responsibility of ZTO TFT reaches around 740 A/W. Additionally, the characteristics of 405nm light-gated ZTO TFT under different gate biases are investigated. The ionized oxygen vacancies generated by light illumination provide a positive electric field. As a result, it is possible to control the transistor with the incident optical power density instead of gate voltage. The drain current versus power density (ID-P) curve showed on/off switching behavior. Besides, the ID-VD curves of light-gated ZTO TFTs are similar to electricity-gated ones where ID increases linearly with increasing VD first and gets saturated after a certain VD value.
EDL Gated FET Biosensor Array for the Investigation of Ion Channels and Bioelectric Signals of Circulating Tumor Cells
Authors: Pulikkathodi Anil Kumar , Sarangadharan Indu , Chen Yi-Hong , Lee Gwo-Bin , Wang Yu-Lin
Published: February 2020

This paper demonstrates the applications of novel high sensitive electrical double layer (EDL) gated FET biosensor array in detecting and counting cells, and analyzing their bioelectric signals in different test conditions. We focused on extremely rare cell type such as Circulating Tumor Cells (CTCs) (HCT-8 cell line) derived from Colorectal Cancer (CRC) cell line. CRC is one of the major forms of cancer that affects human population and CTCs have emerged as a clinical biomarker for diagnosis and prognosis of metastatic CRC. Previously, we had shown that our methodology can detect and count CTCs with very high sensitivity, with up to single cell resolution. Simultaneously, we discovered our sensor platform can be used to dynamically monitor the changes in transmembrane potential (Vm) of the cell, which is an important fundamental bioelectric signal of cell. Studies have shown Vm may be useful as a primary parameter in understanding disease progression, cell signaling mechanism and ion channel gating. We demonstrated that the EDL gated FET sensor can dynamically monitor the changes in Vm induced by high concentrations of extracellular KCl. It was also shown that the sensor response changes as extracellular divalent cation concentrations are dynamically increased towards physiological concentrations. The results display the ability of the sensing platform to monitor the cellular response to dynamically changing, very low ion concentrations as well. Furthermore, an interesting application of bioelectric signal study is demonstrated using cadmium ions to block the calcium channels present in the cell. As shown in figure, in low micro molar concentrations, cadmium acts as a permeant channel blocker (electrically, the cell is depolarized and as the Cd2+ concentration increases, it re-polarizes) and in higher concentrations, it accumulates in the intracellular region (the cell is depolarized again), causing induction of apoptotic signals. The sensor response closely follows the cellular response to permeant channel blockers such as cadmium. These results demonstrate that our sensing methodology can replace the conventional electrophysiological methods or optical potentiometric probes to study fundamental cellular mechanisms such as ion channel gating. Our method offers non-invasive means to monitor changes in Vm, with very high sensitivity for individual cells. The cell based studies can be carried out directly in physiological media with high ionic strength, without the use of extensive pre-treatments or additional reagents.

Figure 1
(Invited) Alternating Current Electroluminescence for Stimuli-Interactive Sensing Display
Authors: Park Cheolmin
Published: February 2020

Development of stimuli-interactive display capable of spontaneously visualizing various external human sensible inputs has been of great interest and tremendous efforts are devoted to the visualization of nonvisible human senses such as touch, smell, taste, and sound. Field induced electroluminescence of either organic or inorganic fluorescent materials under alternating current (AC) has been extensively studied and its unique device architecture in which an emitting layer is separated with an insulator from electrode offers a new platform for designing and developing emerging stimuli-interactive displays. In this presentation, high-performance field-induced AC polymer electroluminescence (AC-PEL) devices are demonstrated with high brightness, high efficiency and color and intensity-tunability. We also present a pressure interactive AC display sensor that allows for both sensing and visualisation of pressure. Light emission upon exposure to an AC field between two electrodes is controlled by the capacitance change of the insulator arising from the pressure applied on top. Besides capacitive pressure sensing, our EL sensor allows for direct visualisation of the static and dynamic information of position, shape, and size of a pressurising object on a non-pixelated single device platform. Finally, the presentation shows that simultaneous sensing and visualization of the conductive substance is achieved when the conductive object is coupled with the light emissive material layer on our novel parallel-type AC-PEL device. A variety of conductive materials can be detected regardless of their work functions, and thus information written by a conductive pen is clearly visualized, as is a human fingerprint with natural conductivity.
(Invited) Transparent Conducting Oxide-Free Flexible Thin Film Electronic Devices and Hybrid Systems
Authors: Guo Wenxi , Xu Zijie , Liu Qian , Li Teng , Zhang Fayin , Xie Shuyao
Published: February 2020

The rapid development of the modern electronics raises higher demands on the flexible and even wearable energy resources. Flexible transparent conducting electrodes (TCEs) are one of the essential components for electronic devices and hybrid systems. Despite commercial ITO on plastics demonstrates superior optoelectronic performances, the low abundance, film britleness, low infrared transmittance and poor chemical stability limit its appications in high flexible and even wearable electronic devices. In this regard,we present highly transparent and conducting ITO-free network film as electrodes for flexible electronic devices and hybrid systems. Thesr These network electrodes not only exhibit remarkable mechanical flexibility under bending tests compared to traditional ITO/plastic substrates, but also superior chemical stability in harsh environment. In addtion, different techniques including electrostatic spinning and crack template were developed to large-area fabricate network TCEs. Such TCE films can achieve a sheet resistance (Rs) as low as ~1.0 Ω sq-1 with transmittance over 85%. Herein, our network electrodes not only served as conducting films for collecting electrons from the external circuit, but also served as superior catalysts for redox reaction at the CE. Thereform, such network TCEs with high flexibility, transparency, conductivity and catalytic activity could be widely used in soalr cells, heaters, electrochromic devices and hybrid energy systems.
Ionic-Strength Dependence of Electron Mobility of Back-Gate Bilayer MoS2 FETs in Aqueous Electrolyte Solutions
Authors: Lu Ming-Pei , Chung Ya-Ting , Lu Ming-Yen
Published: February 2020

In the past few years, atomically thin layered semiconductor materials have attracted numerous interest because of the potential of using those materials to establish liquid–semiconductor sensor systems towards next-generation biological/chemical sensing applications. However, the information regarding the electrical characteristics of 2D materials in aqueous environments for advancing the development of such emerging sensor systems is still unclear. In this report, we have synthesized the bilayer molybdenum disulfide (MoS2) nanomaterials by the chemical vapor deposition method. The layer number of the as-grown MoS2 materials were characterized by using both the Raman spectra and the atomic force microscope (AFM). The selected bilayer MoS2 materials were transferred to a silicon substrate covered with 100 nm-thick SiO2 dielectric layer. The source/drain electrode patterns of the back-gate FETs were defined using an electron beam lithography, followed by the deposition process of the gold thin layer. Importantly, the source/drain electrodes were passivated by the PR layer for reducing the leakage current. After the FET fabrication, the electrical properties of bilayer MoS2 FETs were measured under both the ambient condition and the different concentrations of KCl aqueous electrolyte solutions. From the experimental result of the extracted field-effect mobility, we can evidently find that, when the ionic strength of the KCl electrolyte solution was increased from 0.1 μM to 0.1 M, the values of the ratio of the electron mobility extracted at the aqueous solution to that extracted at the air environment revealed a decreasing trend. The scattering from the ions in the aqueous electrolyte solutions may presumably give rise to the degradation of electron mobility. This report provides information regarding the dependence of the ionic strength on the mobility of atomically thin layered FETs for future sensor applications.
(Keynote) Nanotechnology Approaches to Biological Heterogeneity
Authors: Weiss Paul S.
Published: February 2020

The great promise of single-molecule/assembly measurements is to understand how critical variations in structure, conformation, and environment relate to and control function. New approaches to sensing, imaging, and analysis are keys to elucidating these associations. I will discuss current and upcoming advances and will pose the challenges that lie ahead in creating, developing, and applying new tools for biology and medicine. These advances include using biomolecular recognition in sensor arrays to probe dynamic chemistry in the brain and microbiome systems. They also includes fusing spectroscopic imaging modalities and freeing up bandwidth in measurements to record simultaneous data streams and to expand our dynamic range. Recent advances in sparsity and compressive sensing can be applied both to new analysis methods and to directing measurements so as to assemble and to converge structural and functional information. Early examples will be discussed.
(Invited) Versatile Plasmonic Films for Sensing and Photocatalytic Applications
Authors: Yang Yang
Published: February 2020

Using localized surface plasmon resonance (LSPR) from novel metal nanoparticles for spectrometry-based sensing have been widely investigated. However, sensitivity of conventional plasmonic spectrometry is not high enough for rapid and quantitative detection of molecules. Using LSPR in amperometric sensing is, therefore, considered to be a promising alternative, which may open new possibilities for rapid quantitative detection and fulfill portable sensing requirements by offering low fluid level detection and real-time feedback. However, progress in plasmonic amperometric sensing was slow because it is still challenging to fabricate ideal plasmonic platforms without suffering from powdered nanomaterials aggregation and performance degradation. In this work, a facile solution to these issues is developed using
periodically patterned
Au-TiO2 heterostructures (Au nanorods on TiO2 nanocavities, Au NRs@TiO2) for photoelectrochemical sensor. Generation of plasmonic "hot electron" at Au/TiO2 interfaces was investigated for an enhanced photoelectrochemical detection of glucose and lactose. These rationally designed Au NRs@TiO2 patterned nanostructures possess enhanced sensitivities with a low detection limit of 1 μM (10 μM) and a high sensitivity of 812 μA mM-1 cm-2 (270 μA mM-1 cm-2) for glucose (lactose) detection, which are superior to other Au nanoparticle-based plasmonic sensing systems.
(Invited) Local Probing of Thermally Induced Phenomena in Inorganic/Biological Materials Based on Nonlinear Cantilever Dynamics
Authors: Kim Yunseok
Published: February 2020

Atomic force microscopy (AFM) has been widely used to observe and manipulate physical phenomena at the nanoscale. In AFM, the cantilever is the lens for observing physical phenomena. If we understand how this lens behaves on the material surface, we can understand what kinds of physical phenomena are there and how they interact with the cantilever. Here, I will summarize our recent efforts on the probing of thermally induced phenomena in inorganic/biological samples at the nanoscale based on the nonlinear cantilever dynamics. I will present electrically driven thermal expansion in inorganic materials such as ferroelectric BiFeO3 thin films. It was found that electrically induced nonlinear responses are associated with Joule heating effects. Further, I will also show photo-activated thermal expansion in biological materials such as melanoma and Arabidopsis cells. In general, linear responses of the photo-activated thermal expansion have been widely used for observing chemical and/or thermal information of the organic and biological materials. However, it was found that nonlinear responses can be also useful for identifying local features of the biological materials. These results present that the nonlinear cantilever dynamics in AFM could provide new pathways for exploring fundamental physical properties.
(Invited) Hyperbolic Metamaterials and Their Imaging, Lasing, Sensing Applications
Authors: Rho Junsuk
Published: February 2020

Metamaterials, artificially structured nanomaterials, have enabled unprecedented phenomena such as negative refraction. However, despite the great and promising science, making practical devices based on metamaterials have been one of the most important issues due to the difficulty in fabrication. In this abstract, I will discuss recent development of scalable large-scale nanofabrication efforts to make practical metamaterials-based devices. The example is realizing a super-resolution imaging device of wafer-scale hyperlens, which is the first experimental demonstration of near- to far-field imaging of biological living objects at visible light with resolution beyond the diffraction limit in two lateral dimensions. With proposed hyperlens array, we show the first bio-sample imaging experimental result of super-resolution imaging on hyperlenses by combining to conventional microscopy system for imaging biomolecules. Hippocampal neuron cells are imaged by visible light through the hyperlens array with resolution down to 150 nm, beyond the diffraction limit. The super-resolution imaging result of neuron at sub-diffraction size shows that hyperlens can be used as a useful imaging tools in biology, pathology, medical science and nanotechnology. If time allows, I will discuss the recent progress of sensing and lasing based on hyperbolic metamaterials.
(Invited) A Nature-Inspired Porous Electrode for Flexible, Stretchable Supercapacitors and Lithium-Ion Batteries
Authors: Gao Mengyao , Lin Yan-Cheng , Shih Chien-Chung , Lee Wen-Ya , Chueh Chu-Chen , Chen Wen-Chang
Published: February 2020

Stretchable apparatus have drawn increasing attention nowadays, especially in the applications of sensors, monitors, and optoelectronic devices.1-3 Thus far, the development of stretchable Li-ion battery is impeded by the lack of flexible electrodes associated with proper interconnecting structures for high utilization of active materials.4 As inspired by nature, a common biomaterial, shrimp shells (SSs)5, attracted our attention for fabricating an efficient, stretchable Li-ion batteries as considering its advantages, including i) the C-O, C-N and N-H stretches contained in the protein and chitin (poly-b(1/4)-N-acetyl-D-glucosamine) are beneficial for excellent electrochemical performance; ii) the constituent inorganic calcium carbonate acts as an in-situ template for the porous configuration (Fig. a); iii) The as-designed substrate could not only possess continuous electric conductivity when stretching but also accommodate a high active material loading.

In this work, we successfully demonstrated a flexible, stretchable supercapacitor by using a hybrid electrode, wherein the as-prepared SSs carbon is interpenetrated into a polydimethylsiloxane (PDMS)-supported substrate. In this regard, the open network of pores was filled by the SSs carbon to provide high conductivity and stretchability. Besides, SWCNT was further sprayed onto this porous substrate to form a 3D interconnected porous structure as shown in Fig. b. Finally, by using a bifunctional polymeric electrolyte (BMITFSI-P(EO)20-LiTFSI, serving as separator and solid electrolyte with a high ionic conductivity of 1.6×10-4 S cm-1 to assemble the battery, the as-fabricated stretchable porous electrode can deliver a high energy density of 44.1 Wh kg-1 under 20% applied tensile strain. In addition, the capacitance retention shows 90% after bending from 0o to 180o. This study would pay the way for the future development of wearable supercapacitors, Li-ion batteries and beyond.

W. Liu, M. S. Song, B. Kong and Y. Cui, Advanced Materials, 2016.

D. J. Lipomi, M. Vosgueritchian, B. C. K. Tee, S. L. Hellstrom, J. A. Lee, C. H. Fox and Z. Bao, Nat Nano, 2011, 6, 788-792.

Y. Huang, M. Zhong, F. Shi, X. Liu, Z. Tang, Y. Wang, Y. Huang, H. Hou, X. Xie and C. Zhi, Angewandte Chemie (International ed. in English), 2017, 56, 9141.

W. Liu, Z. Chen, G. Zhou, Y. Sun, H. R. Lee, C. Liu, H. Yao, Z. Bao and Y. Cui, Advanced Materials, 2016, 28, 3578-3583.

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Figure 1
(Invited) Organic Haptics: Soft Materials for Artificial Touch
Authors: Lipomi Darren
Published: February 2020

Human culture is replete with artifacts that interact with the senses of sight, hearing, taste, and smell. Material objects whose purpose is to produce a thoughtful or emotional response through the sense of touch, however, are rare. In this talk, I present my group’s recent work on the intersection between the science of soft materials and the science of touch. This field, which we have named “organic haptics,” combines active polymers, contact mechanics, and psychophysics. We are beginning to understand the ways in which stick slip friction, adhesion, and capillary forces between planar surfaces and human skin affect the ways materials produce tactile objects in consciousness as mediated by the sense of touch. This work, which combines human subject experiments, laboratory mockups of human skin, and analytical models accounting for friction, has led to several important observations. In particular, we have elucidated the mechanism by which humans can differentiate hydrophilic from hydrophobic surfaces when bulk parameters such as hardness, roughness, and thermal conductivity are held constant. We examined the role of relief structures in the skin—i.e., fingerprints—in determining the human ability to differentiate between surfaces. We have taken the insights from these psychophysical experiments to design new electroactive and ionically conductive materials to produce “actuator skins” whose goal is to produce realistic sensations for applications in tactile therapy, instrumented prostheses, education and training, and virtual and augmented reality.
(Invited) Fully-Wireless Health-Monitoring System with Near-Field Communication
Authors: Kim Jeonghyun
Published: February 2020

Recently, many of skin-like or wearable health monitoring sensors have been developed for our convenience. However, most of them still need the wired connector for power and data transmissions. To make fully wireless sensors, the near-field communication technology has been used for wireless communication. The work reported here materials and mechanics ideas for wireless optoelectronic systems that adopt skin-like formats for monitoring the properties of the optical properties the skin and the surrounding environment. Wireless operation of multiplexed arrays of miniaturized, multicolored light emitting diodes couples with digital photodetection and near field communication (NFC) to allow spectroscopic characterization of the skin, in modes compatible with NFC-enabled devices, such as smartphones and tablet computers. Examples in quantitative measurement temporal dynamics of arterial blood flow, blood oxygenation, ultraviolet dosimetry as well as four-color spectroscopic evaluation of the skin demonstrate the versatility of these concepts. The results establish an wireless communication technology platform for optical assessment, suitable use on nearly any region of the body, relevant for clinical care and at-home diagnostics alike.
(Invited) Inkjet-Printed Stretchable Electronic Devices, Circuits, Sensors, and Displays
Authors: Wang Chuan , Cai Le , Zhang Suoming , Zhang Yiheng , Miao Jinshui
Published: February 2020

Stretchable electronic systems built on soft substrates offer more conformal surface coverage and better durability than flexible electronics, and have generated significant research interests recently for potential applications in wearable/implantable health monitoring and diagnostic devices, electronic skin for prosthesis or soft robotics, stretchable displays and many more. Nevertheless, the large-area and low-cost fabrication of high-performance intrinsically stretchable electronic devices has remained to be extremely challenging. In this talk, I will present our recent work on addressing the two major challenges faced by stretchable electronics - the development of intrinsically-stretchable electronic materials and the need for scalable fabrication processes. We have developed nanomaterials-based metal, semiconductor, and dielectric materials with superior electronic property, stretchability, and inter-layer adhesion. Such materials are formulated as electronic inks to allow highly uniform and scalable material patterning using a inkjet-printed process, allowing us to achieve intrinsically stretchable thin-film transistors (TFTs) and integrated logic circuits made entirely by printing on ultrathin elastic polydimethylsiloxane (PDMS) substrates. Electrical and mechanical characterizations reveal that the TFTs and logic circuits can withstand up to 100% tensile strain along either channel length or channel width directions for thousands of cycles while showing no noticeable degradation in electrical performance. In addition to the above, I will also present our work on printed stretchable sensors and displays for wearable electronics and soft robotics applications. Our platform may offer a new entry into more sophisticated stretchable electronic systems with monolithically integrated sensors, actuators, and displays, fabricated by scalable and low-cost methods for real-life applications.
(Invited) Energy Harvesting and Storage in 1D Devices
Authors: Peng Huisheng
Published: February 2020

It is critically important to develop miniature energy storage and conversion devices in modern electronics, e.g., for portable and wearable electronic facilities. Here a novel family of energy storage and conversion devices as well as their integrated devices in 1D configuration are carefully discussed with unique and promising advantages such as lightweight and weaveable compared with the conventional planar architecture. For the energy conversion devices in 1D configuration, fiber-shaped dye-sensitized solar cells, polymer solar cells and perovskite solar cells are covered. For the energy storage devices, fiber-shaped electrochemical capacitors, lithium ion batteries, lithium sulfur batteries, lithium air batteries and zinc air batteries are carefully investigated. The main efforts will be made to highlight the recent advancement in the electrode material, device structure and property extension.
Ghost Floating Gate Effect By Tunneling-Triboelectrification in Graphene Channel
Authors: Kim Tae Yun , Kim Seongsu , Falconi Christian , Kim Sang-Woo
Published: February 2020

Triboelectrification is the electrical charging by friction between two materials. Though the triboelectric effect is reported to have been first observed by Thales of Miletus, it is still a subject of intense research and, recently, has been investigated, with nanoscale spatial resolution, by using atomic force microscopy (AFM). In practice, by rubbing insulators with the tips of AFM, electrical charges can be localized on insulators and be stored for relatively long periods, around one hour. Here we introduce tunneling triboelectrification for defining on demand rewritable ghost floating gates below a 2D material with the nanometer spatial resolution of AFM. Tunneling triboelectrification is the friction-induced tunneling of charges through a 2D material and their accurate localization on the insulator underneath the 2D material. Tunneling of charges may also occur in conventional triboelectrification processes, but in tunneling triboelectrification charges tunnel through a 2D material rather than simply through air or vacuum. Moreover, though charges can be localized even by conventional triboelectrification of dielectrics such as SiO2, the charges injected by tunneling triboelectrification exhibit impressively longer lifetimes (e.g. more than two order of magnitude longer). Finally, after tunneling triboelectrification, the charges very effectively control the properties of the 2D material, thus behaving as immaterial, charges-only, ghost floating gates which can be repeatedly created, modified or destroyed; this unique property may be the key for the development of novel 2D devices which can be drawn or modified on demand.
Designing Carbon-Based Materials for Effective Electrochemical Reduction of CO2
Authors: Siahrostami Samira , Jiang Kun , Kirk Charlotte S , Karamad Mohammadreza , Chan Karen , Wang Haotian , Nørskov Jens
Published: February 2020

Electrochemical reduction of CO2 (CO2RR) using renewable electricity has emerged as an attractive approach to synthesize hydrocarbons and mitigate atmospheric CO2 concentration. Carbon-based materials have recently attracted a particular attention as electrocatalysts for CO2RR due to their extraordinary properties such as low cost and flexibility in tuning the morphology and electronic structure. Wide range of different N-doped carbon materials have been experimentally tested and reported for CO2RR. The performance map for CO2RR over reported N-doped carbon-based materials presents diverse activities and in most cases the major product of the CO2 reduction is found to be CO. Based on a simple thermochemical analysis Wu et al previously suggested pyridinic-N as the active sites.1 Using density functional theory (DFT) calculations we study a wide range of different possible active motifs included in the defective carbon materials to rationalize the associated trends in their intrinsic activities. We study both CO2RR and hydrogen evolution reaction (HER) using thermochemical analysis. We identify several active motifs that are expected to exhibit a comparable or even better activity to the state-of-the-art gold catalyst, and several configurations are suggested to be selective for CO2RR over HER. This study provides insights in the nature of active and selective motifs for CO2RR and rationalizes a number of reports in the literature.2 We also show that in the presence of metal impurities further reduced products can be synthesized with significantly improved activity and selectivity.

References:

(1) Wu, J.; Yadav, R. M.; Liu, M.; Sharma, P. P.; Tiwary, C. S.; Ma, L.; Zou, X.; Zhou, X.-D.; Yakobson, B. I.; Lou, J.; Ajayan, P. M. ACS Nano
2015, 9 (5), 5364–5371.

(2) Siahrostami, S.; Jiang, K.; Karamad, M.; Chan, K.; Wang, H.; Nørskov, J. ACS Sustain. Chem. Eng.
2017, acssuschemeng.7b03031.

(3) Jiang, K.; Siahrostami, S.; Li, Y.; Lu, Z.; Gardener, J.; Lattimer, J; Stokes, C.; Hill, W.; Bell, D.; Chan, K.; Nørskov, J.K.; Yi Cui, Y.; Wang, H. Chem
2017 https://doi.org/10.1016/j.chempr.2017.09.014.
Quasi-2D Pd/Pt Nanoclams for CO2 Reduction in Tandem with Microbial Communities
Authors: Wong Andrew Barnabas , Kracke Frauke , Antoniuk-Pablant Antaeres Dawn , Hahn Christopher , Spormann Alfred M , Jaramillo Thomas F
Published: February 2020

Improving the performance of cathodes for the electrochemical CO2 reduction reaction (CO2RR) will benefit from the discovery of new materials as well as the introduction of new paradigms for the development of integrated systems. This poster presents work on the synthesis and CO2 reduction activity of a novel quasi-2D Pd/Pt bimetallic ‘nanoclam’ catalyst synthesized on carbon cloth electrodes as well as the integration of these novel nanostructured cathodes with microbial communities. The integration of microbial communities with these nanostructured Pd/Pt catalysts has the potential to combine the best-of-both-worlds from electrochemical and biological systems to achieve a regenerative catalytic system with high-selectivity, high activity, and low overpotential.
Metal Sulfides As Catalysts for the Electrochemical Reduction of Carbon Dioxide
Authors: Xu Wutao , Zhang Qi , Liu Yuyu , Zhang Jiujun
Published: February 2020

Electrochemical reduction of carbon dioxide (ERC) is a promising way to solve the greenhouse effect and energy issues. We look forward to finding efficient, durable and cost-effective catalysts for the practical application of ERC. Metal sulfides can be used as desirable catalysts for ERC. Sulfides of transition metals are considered as catalyst candidates for the ERC in this study. Selected metal sulfides are coated on carbon paper to get the gas diffusion electrode (GDE), which are then used to catalyze the ERC in KHCO3 solution. Their electrocatalystic activity, product selectivity and durability for ERC were evaluated by cyclic voltammetry and linear sweep voltammetry. The structures of them are investigated by using SEM, TEM, etc. To confirm the influence of different synthesis methods on the performance, we used hydrothermal and chemical synthesis to prepare the metal sulfides. The results indicated the desirable electrochemical catalytic performance.