bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D Printing of Molds for Soft Lithography
Authors: Shah Shreyas , Shiblee MD Nahin Islam , Furukawa Hidemitsu , Kawakami Masaru , Nagahara Larry A , Thundat Thomas , Sekhar Praveen K. , Khosla Ajit 
Published: February 2020

Microfabrication of PDMS based microfluidic devices involves fabrication of micromolds which need expensive infrastructure, such as clean room, photolithography equipment, photoresists, substrates, masks etc. In this paper, we present fabrication of micromolds using three dimension (3D) printing for soft lithography [1, 2]. By employing 3D printing technology overcomes the challenges posed by time consuming and difficult to manufacture, with state of the art 2-D MEMS fabrication technology [3]. Compared to the conventional method of microfabrication, 3D printed mold can be processed more rapidly, augment use of materials, intricate design which is challenging by photolithography [4,5]. Here, we designed and fabricated micro features using binder jetting printer (Objet30 Pro) and photopolymer jetting printer (Formlabs Form 2). Objet30 Pro uses the technique of depositing adhesive liquid onto the powder photopolymer on the build tray. Binding process between the powdered particles make a solid structure. During the printing of master no support structures where used. The master was also printed using the deposition of photopolymer using the Formlabs Form 2 printer. Concept behind the fabrication is curing the photopolymer by UV light which is deposited pointwise layer-by layer. Since, the fabrication of the master is done in slices the surface of the master was rutted which gave bumpy replication but, were able to print the feature (Round trench, Hexagonal trench) size of 200μm (Fig 1 and 2). Mold fabricated using the Objet30 pro printer gave fine structures with resolution of 300μm in depth and feature size of 500μm were printed flawless. This technique forms a 3D printed structure by holding the particles and does not require support structure.
References:

Khosla, Ajit, and Bonnie L. Gray. "(Invited) Micropatternable Multifunctional Nanocomposite Polymers for Flexible Soft NEMS and MEMS Applications." ECS Transactions 45.3 (2012): 477-494. doi: 10.1149/1.3700913

Khosla, A. (2011). Micropatternable multifunctional nanocomposite polymers for flexible soft MEMS applications (Doctoral dissertation, Applied Science: School of Engineering Science). http://summit.sfu.ca/item/12017

Khosla, Ajit. "Nanoparticle-doped electrically-conducting polymers for flexible nano-micro Systems." The Electrochemical Society Interface 21.3-4 (2012): 67-70.doi: 10.1149/2.F04123-4if

Takamatsu, K., Basher, S., He, S., Sato, K., Yoshida, K., Sakai, K., ... & Khosla, A. (2017, September). 3D Printing of Micromolds and Microfluidic Devices. In Meeting Abstracts(No. 49, pp. 2113-2113). The Electrochemical Society.

Takamatsu, K., Yamada, N., Wada, M., Ahmed, K., Kawakami, M., Kassegne, S., ... & Khosla, A. (2016, September). 3-D Printed Polymer MEMS. In Meeting Abstracts (No. 51, pp. 3861-3861). The Electrochemical Society.

Figure 1
Sub-Nanomolar Detection of Limonin Using Cnps Integrated Silk Fibroin As Transducer on Organic Electrochemical Transistor
Authors: Saraf Nileshi , Barkam Swetha , Peppler Madison , Seal Sudipta , Metke Anna 
Published: February 2020

Limonin is a biomolecule which is responsible for the bitter element in many citrus fruits and vegetables. It has proven to be antioxidants which are biologically active and exhibit anticarcinogenic activity. It is formed from a tasteless precursor called limonite β ring lactone, which is found in the juice sacs. During juice extraction from the fruit, the precursor encounters the acidic compound of the juice and is gradually lactonized to form bitter limonin. This bitterness is generally not desired, therefore quantification and detection of limonin is very crucial for improving fruit quality in the citrus industry. The current techniques available for detecting limonin in fruits are time consuming, expensive and not fit for active monitoring of limonin levels.
In this study, we have shown the applicability of ceria nanoparticles (CNPs) to be used as a transducer integrated in silk fibroins that is coupled with an organic electrochemical transistor to detect limonin. CNPs possess antioxidant properties which is attributed to the redox nature of dual oxidations states, Ce3+ and Ce4+, switching on the surface. This constant switching of oxidation states on the surface produce oxygen vacancies that act like hot spots for targeting electroactive entities like limonin. Therefore, in the present work, the electrochemical interaction between CNPs and limonin has been exploited to detect limonin using a transistor platform. Multiple characterization techniques were done to confirm the presence of CNPs in silk fibroins. The SOD and the catalase mimetic activity was assessed using SOD assay kit and Amplex red kit which showed the preservation of CNPs antioxidant properties in silk. Immobilizing and embedding CNPs in silk fibroins was studied to provide the most sensitive and efficient transducer for the OECT. In order to find the limit of detection of the OECT, limonin concentrations were varied and tested at different gate voltage (VG). The limonin OECT prepared in this study showed a detection limit of 10nM with a constant increase in the ID current with limonin concentration. A range of interfering species which are commonly available in citrus fruits, were also tested to investigate the selectivity of the sensor. It was observed that none of the analytes, other than the limonin, produced a noticeable change in current. Thus, the CNPs-OECT limonin sensor has potential applications in sensing limonin on field applications. Future field and research application of the CNPs-OECT sensor could include real time monitoring of the amount of limonin in fruit juices or to study and reduce the amount of limonin in citrus fruits and to quantify the dosage of limonin as a potential antioxidant material.
Fabrication of MEMS Electronics Devices Based on Fire-like ZnO Nanosheets By Low-Temperature Hydrothermal Synthesis Technology
Authors: Tsai You-Ting , Chang Shoou-Jinn , Hsiao Yu-Jen , Chu Yen-Lin , Tang I-Tseng , Ji Liang-Wen 
Published: February 2020

The high-density novel morphology fire-like Zinc Oxide (ZnO) nanosheets grown on aluminum (Al) substrate. The fire-like ZnO nanosheets based MEMS technology gas sensors using zinc nitrate hexahydrate, and hexamethylenetetramine by using a low-temperature hydrothermal method. The structure and optical characteristics of fire-like ZnO nanosheets were measured by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The FE-SEM images show that the new morphology was fabricated and high of the ZnO nanosheets can be controlled by the different thickness of Al substrates, it was found that measured high of the ZnO nanosheets increased from 733.3 nm to 2000 nm and the response of ethanol was increased due to the high surface area nanosheets.
Keywords: Al thin films, hydrothermal, ZnO nanosheets

Figure 1
Limitations in Estimation of E1/2 from Cyclic Voltammetric Data
Authors: Parr Daniel , Leddy Johna 
Published: February 2020

It is common practice to estimate the standard (E0) or formal (E0’) potential from cyclic voltammetric data. A frequent estimate of E0 or E0’ is taken from either the peak potential (Ep), the half wave potential (E1/2), or the average of the cathodic and anodic peak potentials (Epc+Epa)/2. Often, this suffices to identify the standard or formal potential within 100 mV, but confidence in such estimates is not always justified. Mechanisms that include both electron transfer (E) and chemical (C) steps can impact the quality of estimated standard and formal potentials. In some systems, limitations to the estimated standard and formal potentials depend on the rates of heterogeneous electron transfer and homogenous reactions.
Here, the quality of estimated standard and formal potentials based on peak potentials, half-wave potentials, and average potentials for the cathodic and anodic sweeps are described for various mechanisms. Cases where the standard and formal potentials are well estimated from measured cyclic voltammetric data are identified and the quality of the estimated standard and formal potentials are characterized. That is, specify whether the estimate is within 100 mV, 50 mV, or 10 mV for a given mechanism. Situations where the estimate fails are identified and alternative means to estimate the standard and formal potential are provided. Several reaction schemes that include EC, EE, CE, and the various ECE mechanisms are characterized.
Electrical and Structural Properties of ZrO2/Y2O3/ZrO2 Dielectric Film for DRAM Capacitor
Authors: Cho Seong Tak , An Cheol Hyun , Kim Sang Hyeon , Kim Dong Gun , Kwon Dae Seon , Cha Soon Hyung , Hwang C. S. 
Published: February 2020

ZrO2/Al2O3/ZrO2 (ZAZ) structure is widely used as a capacitor dielectric film of Dynamic Random Access Memory (DRAM). This is a structure in which Al2O3 film is added as an interlayer to improve the leakage current in the ZrO2 material which can meet the dielectric constant and leakage characteristics required by the device. Nonetheless, the added Al2O3 film decreases capacitance density compared with a capacitor composed of the single ZrO2 layer, because the Al2O3 film itself has a low dielectric constant and the upper ZrO2 film is not crystallized properly. Although this ZAZ structure has been extensively used to meet the device requirements of DRAMs down to the design rule of ~20nm, it is difficult to further use it for the DRAM with design rule lower than 20nm. Accordingly, there are active research and studies in progress to discover a new dielectric material to replace the ZAZ structure.
In this study, Y2O3 was used to replace Al2O3 to suggest a strategy to increase the total dielectric constant while maintaining the role of improving the leakage characteristics performed by the Al2O3 film. The dielectric constant and bandgap of Y2O3 are higher than that of Al2O3 and that of ZrO2, respectively, and it is also known as a material stabilizing the phase of ZrO2 into high-k phase.[1] Therefore, Y2O3 is considered a promising candidate to replace Al2O3.
The evaluation was carried out using Y(iPrCp)2(iPr-amd) precursor, synthesized by Air Liquide Co., which is liquid at room temperature, and O3 as the oxygen source. The saturated deposition rate of the Y2O3 thin film was ~0.14nm/cycle when it was grown by an atomic layer deposition (ALD) method. Cubic phase Y2O3 film was observed by X-ray diffraction.
For comparison, ZAZ and ZrO2/Y2O3/ZrO2(ZYZ) were deposited on TiN substrate by ALD method, and their electrical and physical properties were evaluated. As expected, the equivalent oxide thickness could be decreased by ~0.2nm at a physical thickness of ~10nm, while the leakage current level remained almost invariant (~9 X 10-
10A/cm2 to ~4 X 10-
9A/cm2 at 0.8V) when the Al2O3 was replaced with the Y2O3 layer. The effect of heat treatment on the crystal structure of ZrO2 in ZAZ and ZYZ dielectric films and the electrical properties according to variations in their thickness were also studied. These results are promising as the newly suggested ZYZ structure may replace the present ZAZ without any major changes in electrode and integration strategy.

References [1] Bo-Eun Park et al., Journal of Alloys and Compounds 722 (2017)

Figure 1
A Paper-Based Spectroelectrochemical Platform Integrated with Electrodes and Surface Enhanced Raman Scattering Zones
Authors: Andersen Nalin I , Artyushkova Kateryna , Gonzales Ivana , Atanassov Plamen 
Published: February 2020

We report the fabrication and use of a paper-based analytical system to study multiple modalities of catalysts utilized for the same global reaction. Presented here is a porous media device that couples quasi-stationary flow, stencil-printed electrodes, and surface enhanced Raman spectroscopy zones for rapid determination of catalytic transformations. The methodology of a paper-based platform is extended to demonstrate how multiple chemical reactions can be performed in sequence by use of both enzymes and electrocatalysts. Enzymes play a contributing role in the electrocatalytic conversion of glycerol to carbon dioxide, which is a complex cascade system 1,2. Specifically, the use of oxalate decarboxylase has been shown to catalyze the conversion of mesoxalic acid (6) to glyoxylic acid (7) and oxalic acid (8) to formic acid (9) as shown in Figure 1. The platform allows rapid determination of catalytically transformed analytes. It also serves as a method for understanding the optimum reaction conditions necessary for using different modalities of catalysts together.
References:

Hickey, D. P., McCammant, M. S., Giroud, F., Sigman, M. S. & Minteer, S. D. Hybrid enzymatic and organic electrocatalytic cascade for the complete oxidation of glycerol. J. Am. Chem. Soc.
136, 15917–15920 (2014).

Abdellaoui, S., Hickey, D. P., Stephens, A. R. & Minteer, S. D. Recombinant oxalate decarboxylase: enhancement of a hybrid catalytic cascade for the complete electro-oxidation of glycerol. Chem. Commun.
51, 14330–14333 (2015).

Figure 1
Microstructural Effects on Disorder and Transport in Irradiated Pyrochlore Thin Films
Authors: Parker Nia , Kreller Cortney R. , Valdez James Anthony , Holesinger Terry , Wang Yongqiang , Tang Ming , Uberuaga Blas 
Published: February 2020

Complex oxides exhibiting fast ion conduction have surfaced as attractive materials for various applications such as fuel cells, electrolyzers, sensors and gas separation membranes. Literature shows that many of the studies of these materials place emphasis on improving ionic conductivity. Here we focus on improving our understanding of how defects within the microstructure impact ionic transport.
We employ irradiation as a tool to induce disorder in oxide materials, then utilize a number of different characterization techniques to determine the relationship between disorder and oxygen ion conduction. In this study, Gd2Ti2O7 (GTO) pyrochlore thin films are prepared on single and polycrystalline Yttria Stabilized Zirconia (YSZ) substrates using RF Magnetron sputtering. Electrochemical Impedance Spectroscopy measurements are performed as a function of temperature in the through-plane configuration using a Cascade Microtech Microprobe Test Station equipped with a Linkam high temperature stage. The EIS data is used to determine the conductivity of GTO films with varying degrees of irradiation induced structural disorder. This work examines how the underlying microstructure in polycrystalline and highly oriented thin films (grown on polycrystalline and single crystal YSZ substrates, respectively) influences irradiation induced disordering and transport properties.

Acknowledgements

This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.
Room-Temperature Atomic Layer Deposition of Aluminum Silicate for Molecule Sorption
Authors: Mori Yoshiharu , Imai Takahiro , Kanomata Kensaku , Miura Masanori , Ahmmad Bashir , Kubota Shigeru , Hirose Fumihiko 
Published: February 2020

A room-temperature atomic layer deposition (RT-ALD) of aluminum silicate for molecule sorption is developed using trimethylaluminum (TMA) and trismethylaminosilane (TDMAS) using a plasma excited humidified argon. The aluminum-silicate is a main material of zeolites that is used for cation sorption. If we achieved the aluminum silicate deposition on flexible films, we could expect the film used as a regenerable ion exchange filter.
The schematic of ALD system is shown in Fig.1. TMA and TDMAS were introduced with mass flow controllers. A remote plasma system generating excited humidified argon was installed to the ALD chamber. The source gas for the oxidizing gas is a mixture of water vapor and argon. The plasma was generated in a glass tube with an induction coil with a frequency of 13.56 MHz and a RF power of 100 W. For the deposition, we repeated the cycle of TDMAS and TMA saturation and oxidizing gas treatment at RT. To control the aluminum to Si atomic ratio in the aluminum silicate, we adjusted the initial exposure of TDMAS.
To confirm the Na sorption ability of the aluminum silicate film deposited by the present technology, we immersed the aluminum silicate coated Si sample in a 100 mM NaCl solution for 3h. The dried sample was evaluated by X-ray photoelectron spectroscopy. As shown in Fig. 2, the enhanced Na adsorption is confirmed. In the conference, we discuss the mechanism of Na sorption on the RT deposited aluminum silicate.

Acknowledgements
This work was partly supported by JSPS KAKENHI Grant Numbers 15H03536. It was also partly supported by JST-CREST Grant Number JPMJCR14F3, Japan.

Figure 1
Aqueous Phase Synthesis Method of Fe Metal Nanoparticles and Its Application for Commercial Materials
Authors: Takahashi Hideyuki 
Published: February 2020

It is well known that the melting point of metal element drastically change with decreasing the diameter of its particle into nano level, by obeying to the equation as follows,
Tnano = Tbulk (1-2σ/(ΔH*R))
Here, Tnano is melting point of nanoparticles. Tbulk is melting point of bulk material, σ is surface energy, ΔH is enthalpy change of melting, and R is radius.
Thus, the development of effective and green synthesis method of Fe nanoparticles means the development of new bonding method of Irons at low temperature, since Fe is most basic materials in resent world.
Fe nanoparticles were synthesized only in acidic solution by using strong reducing reagent, while it cannot be achieved in basic solution since iron hydroxide, which is easily formed in this condition, cannot be reduced into metals. However, former is not suitable for commercial synthesis method because of its intense reducing process. Thus, the reducing rout of Fe species under basic condition should be developed.
Here, until now, we tried to synthesized various metal/alloy nanoparticles, such as Pd20Te7 nanoparticles and uniform Cu-In (CI) alloy nanoparticles, by utilizing the restrict metallic complexes controlling method in an aqueous solution under room temperature. In this method, reduction potential of the metal species can be controlled under the room temperature, consequently metal/alloy nanomaterials with uniform and well crystallized structure can be successfully synthesized.
Therefore, in this study, aqueous phase synthesis method of Fe metal nanoparticles were developed.
To achieve the homogeneous reaction condition, metal complex species in the aqueous phase were restricted into single species by using calculation. Reduction potential of homogenized metal complex were analyzed by using cyclic voltammetry. Fe nanoparticles were synthesized by using chemical reduction method under ambient conditions using metal chlorides as metal sources and sodium borohydride as a reducing agent.
Calculation results indicated that Fe complex can be restricted into one species as the function of pH, complexing reagent species and/also concentration. For example, Fe complex can be restricted into Fe(NTA)2 only, in the case of 8<pH<11.
By using these homogeneous condition, metal Fe nanoparticles were successfully synthesized.
Other results, such as melting and/or bonding condition of synthesized materials, will present in our presentation.
[1] H. Takahashi et.,al, Applied Catalysis A: General 392 (2011) 80–85
Investigation on Electrical Properties of Hydrogen Doped Boron Carbide Thin Films
Authors: Nehate Shraddha , Sundaram Kalpathy B 
Published: February 2020

The ever-increasing advancements in semiconductor technology and continuous scaling of CMOS devices demands need for new low-k dielectric materials. Boron Carbide (B4C) has attracted recent attention due to its complicated crystalline structure and interesting properties. B4C is the third hardest material with a hardness > 30GPa after diamond and cubic boron nitride [1]. However, with increase in temperature, the hardness of diamond and cubic boron nitride decreases gradually. B4C is characterized to be the hardest material at even above 1100°C [2]. Other interesting properties exhibited by boron carbide are low specific weight, high modulus, high chemical stability and good wear resistance. These properties make boron carbide a promising material for applications in cutting tools.
In this study, electrical properties of hydrogen doped boron carbide thin films will be investigated. Boron carbide films are deposited by magnetron RF sputtering of B4C target. Films are deposited at different temperatures in presence of hydrogen/argon gas to investigate the influence of temperature and hydrogen on electrical properties of boron carbide thin films.
References
[1] T. Eckardt ,U, K. Bewiloguaa , G. van der Kolkb , T. Hurkmansb , T. Trinhb , W. Fleischer, Improving tribological properties of sputtered boron carbide coatings by process modifications., Surf. Coat. Technol., 123 (2000), p. 69
[2] S. Ulrich, H.Ehrhardt, J.Schwan, R.Samlenski, R.Brenn, Subplantation effect in magnetron sputtered superhard boron carbide films, Diamond Relat. Mater., 7 (1998), p. 838
Synthesis and Photoluminescence Properties of (Sr, Ba)2-XEuxSiO4 Phosphors with High Eu2+ Concentration for White LED Applications
Authors: Sato Yasushi , Tomita Koji , Kakihana Masato 
Published: February 2020

Recently, several oxide-based phosphors with excellent luminescence properties have been reported. Especially, the deep-red emitting Ca1.2Eu0.8SiO4 has been prepared by the basis on crystal-site engineering, which shows an emission peak at 653 nm under excitation at 450 nm [1]. The emission wavelength of Ca1.2Eu0.8SiO4 is quite similar to those of commercial red-emitting CaAlSiN3:Eu2+ and Sr2Si5N8:Eu2+. The crystal structure of Ca2-x
Eu
x
SiO4 is analogous to those of Sr2-x
Eu
x
SiO4 and Ba2-x
Eu
x
SiO4. Therefore, it is expected that the addition of large amounts of Eu2+ ions to Sr2-x
Eu
x
SiO4 and Ba2-x
Eu
x
SiO4 can also lead to large redshifts in their emission and excitation spectra. In this study, we prepared and characterized Sr2-x
Eu
x
SiO4 and Ba2-x
Eu
x
SiO4 with a high concentration of Eu2+ ions. In the case of Sr2-x
Eu
x
SiO4, the emission peak was shifted from 585 nm for Sr1.9Eu0.1SiO4 to 611 nm for Sr1.2Eu0.8SiO4. On the other hand, in the case of Ba2-x
Eu
x
SiO4, the emission peak was shifted from 513 nm for Ba1.9Eu0.1SiO4 to 545 nm for Ba1.2Eu0.8SiO4. The right-hand edges of the excitation spectra for both the samples were significantly shifted, by 40-55 nm, to longer wavelengths, allowing for excitation by blue light. The induction of large redshifts in the emission and excitation spectra of both samples could be attributed to the occupancy of Eu2+ ions in the polyhedra of Sr(2) or Ba(2) sites, which are smaller and more distorted than the Sr(1) or Ba(1) sites. These results indicate that Sr1.2Eu0.8SiO4 and Ba1.2Eu0.8SiO4 are suitable as red- and green-emitting phosphors for next-generation white-LED applications.
[1] Y. Sato and M. Kakihana et al., Angew. Chem. Int. Ed.
53 (2014) 7756.