We explored a new fluid flux stabilized even in the vacuum condition at high temperature by combinatorial pulsed laser deposition (PLD) approach. A small amount of CuO doped in BiOx was found to effectively stabilize BiOx even in 6 Torr O2 at 800°C. The application of this novel Bi-Cu-O flux to the vacuum process lead to the successful fabrication of a single crystal Bi4Ti3O12 film and the establishment of a more reliable process for preparation of an atomically flat LaAlO3(001) substrate.

Studies of combinatorial fabrication and screening of organic light-emitting devices (OLEDs) are reviewed. These studies include screening of luminescent materials, electron and hole transport layers, lower-gap emitting guest dopants in small molecular emitters, and electronically doped polymeric anodes. The review focuses on screening of 2-dimensional (2-d) small molecular UV/violet arrays, 1-d blue-to-red arrays, and 1-d intense white OLED libraries, and briefly describes arrays fabricated to study Förster energy transfer in guest-host OLEDs. It demonstrates that combinatorial fabrication of OLEDs has become a powerful tool for screening OLED materials and configurations, and for studying their basic properties.

High-throughput screening experimentation and multivariate spectral data analysis has been applied to evaluate the gas sensitivity of multi-size CdSe nanocrystals embedded in multiple polymer matrices. We have found that when CdSe nanocrystals of different size (2.8 and 5.6 nm diameter) were incorporated into polymer films, the photoluminescence (PL) response patterns upon laser excitation at 407-nm and exposure to polar and non-polar solvents were unexpectedly different. Additionally, these response patterns were dependent on the nature of polymer. We analyzed the spectral PL response from both sizes of CdSe nanocrystals using multivariate analysis tools. Results of this multivariate analysis demonstrate that a single film with different size CdSe nanocrystals serves as a selective sensor.

In this study, we are demonstrating localized nano-scale analysis of sensor materials which are developed using combinatorial gradient approach. Our technique based on Focused Ion Beam cross-sectioning at specific locations affords establishing metal nano-particles concentrations at best-performing area(s) of gradient-formulated polymer samples. We have achieved three-dimensional characterization/mapping of nano-fillers (30-100 nm metal particles) in composite thin films on variety of substrates.

The potential of applying photoelectron spectroscopic and Kelvin probe methods for the interface potential evaluation of materials prepared by combinatorial processes is demonstrated. The physical basis for the evaluation of the interface potential by photoelectron spectroscopy is given. Then, the imaging capability of photoelectron spectroscopy is demonstrated using a two-dimensionally patterned specimen. Finally, the examples of interface potential evaluation with photoelectron spectroscopy and Kelvin probe are presented. Through the evaluation of interface potential with this method, it is possible to deduce the energy level diagram across the interface between two materials with different electron properties.

We are developing a measurement platform, based on the edge delamination test geometry, geared towards combinatorial and high-throughput (C&HT) assessment of interfacial adhesion and reliability of epoxy films bonded to a rigid substrate. A critical parameter space to be explored is composition of the epoxy formulation. We have constructed an automated mixing and deposition system for creating discrete and continuous gradients in composition of viscous epoxy formulations. By dicing the combinatorial library into a contiguous discrete sample array, the interfacial adhesion strength can be deduced from the critical stress required to debond each film cell from the substrate. These results can be used to predict the adhesion reliability of epoxy formulations as a function of composition and applied stress.

Ab initio calculations based on density functional theory (DFT) have been used to study the energetics, fully relaxed structure, charge redistribution, and electronic density of states of adsorbed atomic and molecular oxygen on defectless unreconstructed SrO- and TiO2-terminated SrTiO3(001) surfaces. Exchange-correlation functional applied within DFT contains a “hybrid” of the non-local Hartree–Fock exchange, DFT exchange, and generalized gradient approximation correlation functionals. The calculations are performed on periodically repeated systems (two-dimensional slabs) large enough for the adsorbed species to be treated as isolated. We find substantial binding energies of up to 1.8 eV for atomic oxygen adsorption over surface oxygen and of over 2.0 eV at bridge (position between two adjacent surface atoms) sites of both SrO- and TiO2-terminated surface. A range of different adsorption sites and orientations for molecular oxygen have been studied but practically in no case does the adsorption energy exceed 0.1 eV. The stability diagram of surface structures in contact with a gaseous oxygen environment is calculated by means of atomistic thermodynamics. Adsorption of the reactants is found to depend significantly on temperature and partial pressures in the gas phase.

We developed a variable-temperature scanning microwave microscope (VT-SμM) that can perform high-throughput materials characterization in the temperature range between 4K and room temperature. As a sensor probe we used a high-Q coaxial cavity resonator, which was mounted on the low-temperature stage to allow variable-temperature measurements. We carried out systematic studies on the thermal degradation of the conducting polymers using the combinatorial libraries of polyaniline and polythiophene thin films, which showed rapid decrease of conductivity above 300C and 250C, respectively. The low-temperature performance of the VT-SμM was demonstrated by the measurement of composition-spread Nd1-xSrxMnO3 thin film, for which we succeeded in detecting the clear metal-insulator transition at 100K. We also propose a simple and easy method for the quantitative analysis of conductive thin films, by using the standard composition-spread thin films of Ti1-xNbxO2.

We discuss visualization and data dependency issues related to managing sample characterization data from high-throughput experiments. We are developing software for on-line storage, sharing, and visualization of data from combinatorial or high-throughput experiments. The system is based on a centralized database and a Web interface that can be accessed from any networked computer. The greatest challenge facing us is the variety of data types and formats that such a system has to support so that data from many different sources, i.e. from synthesis and characterization instruments, could be combined. In order to minimize the software development effort, we have developed generalized extensible markup language (XML) schema for storing and processing experimental data. The use of a standard data format like XML, together with the relevant schema definitions can be used to implement storage, processing, visualization and other tools that are generic and thus greatly simplify the task of managing high-throughput experiments.

Screening of materials arrays for their viscoelastic, gas-sorbing, and electrical properties is important for a variety of practical applications ranging from sensor to protective coatings. Complex impedance analysis of the materials arrays is an attractive approach to analyze these materials properties. We developed a wireless proximity sensor array system for combinatorial screening of these types of materials and demonstrated its applicability for sensor materials. In the developed system, sensor materials are applied onto an array of resonators and arranged for performance testing in a test chamber. Each resonator is coupled to a receiver antenna. An array of these antennas is read with a single scanning transmitter antenna or an array of transmitter antennas. Such high-throughput screening approach of sensor materials permits their evaluation in complex environments where additional wiring is not desirable or adds a prohibitively complex design.

The photoluminescence (PL) properties of Mn-doped zinc silicates were studied by combinatorial synthesis and characterization technique associated with various process parameters. The material libraries were prepared with composition spreading in Zn and Mn concentration. The PL emission was green or orange, and depended strongly on the stoichiometry of the zinc silicates and the annealing temperature. The orange emission was observed in Mn-doped zinc silicates annealed at 800°C, which attributed to the increase of crystal field in a highly non-stoichiometric α-Zn2SiO phase ((Zn+Mn)/Si <1).

Combinatorial catalysis on EtOH steam reforming has been performed on referring catalysis database on elemental reactions of EtOH SR.

With the development of combinatorial materials research (CMR) methods and high throughput experimentation (HTE) workflows for polymer research applications, the demand for automated, high throughput characterization methods is evident. Solution-based characterization methods like NMR, GPC, viscosimetry, for example and UV-Vis as well as fluorescence plate readers are available. Here we report on the incorporation of automated scanning probe microscopy in the HTE-workflow by demonstrating the evaluation of surface properties and topographies for thin polymer film libraries.

This paper discusses the design and use of gradient annealing devices. Generally, it is intended to use such devices for the rapid optimization of thin film materials by simultaneous thermal processing at different temperatures. Furthermore, these devices are efficient for short- time annealing experiments. They are used in order to quickly vary the annealing parameters (temperature, time) from sample to sample. Here, nanoscale Fe/Pt multilayer precursor thin films for the fabrication of hard magnetic Fe-Pt thin films are investigated as a test system. First results prove the usefulness of the gradient annealing devices for high-throughput experiments.

A combinatorial workflow for developing organic surface coatings has been developed. The workflow is uniquely designed to prepare and evaluate marine coatings that prevent biofouling on the hulls of ships. A critical component of the workflow is the high throughput screening of settlement and ease of removal of marine organisms from coating surfaces. Methods have been developed to directly and indirectly quantify marine bacterial biofilm growth and retention. Correlations have been developed between these high throughput bioassays and results from ocean testing.

The use of combinatorial libraries for screening cell-material interactions presents a significant need for robust informatics methods capable of extracting knowledge from large, combinatorial datasets. We describe the development of local quantitative metrics based on distributions of other cells and microstructures about each individual cell. The local metrics are shown to be superior to global, summary statistics in detecting sensitive effects of surface microstructure on proliferation of MC3T3-E1 osteoblasts.

Combinatorial experiments provide a means of generating large amounts of experimental data; however that does not necessarily lead to high throughput interpretation of that data. In this paper we provide a brief summary of how one can use informatics techniques to accelerate data interpretation from high throughput experiments. We provide examples from high throughput nanoindentation and diffraction experiments.

α/β type titanium alloys, such as Ti-6Al-4V and Ti-6Al-7Nb, have been used for orthopedic implant materials because of their combination of biocompatibility, corrosion resistance and mechanical properties. However, toxicity of alloying elements is a concern.

In this project, it is proposed to design the new type of titanium alloys composed of non-toxic elements, such as Ti, Al, and Fe with lower modulus of elasticity and greater corrosion resistance. To find the optimal ratio of components in the Ti-Al-Fe system is important. The composition of the alloy determines its properties. Using combinatorial approach the optimal ratio can be found relatively easily.

Direct metal deposition (DMD) is a novel precise manufacturing process for fabricating metal parts directly from Computer Aided Design (CAD) solid models. The DMD process allows making several layers of different composition on one substrate. One sample includes several Ti-xAl-yFe alloys at once. This combinatorial library dramatically reduces the time and cost of the investigation.

The structure, mechanical and electrochemical properties of each new composition was studied using scanning electron microscopy (SEM) with energy-dispersive X-ray fluorescence analyzer (EDAX ZAF®), and electrochemical polarization method.

A newly developed high-throughput exploration system “M-ist Combi” can control mixing ration of five-component compounds. Furthermore, the M-ist Combi system can also be obtained not only thin film but also powder and liquid libraries by controlling applied voltage and used flexibly in either a normal atmosphere or controlled atmosphere. By combining the M-ist Combi system with combinatorial XRD apparatus, we successfully completed the high-throughput powder preparation and phase identification of over 150 samples in one day.

Combinatorial arc plasma deposition (CAPD) method was used to search for new compositions of thin film amorphous alloys. A cathodic arc plasma gun (APG) was adopted as the deposition source for CAPD. The CAPD setup has three APGs radiating out from the center of a substrate. The APGs shoot pulse-like plasma shots one by one at a specific time interval. The plasma from each APG cathode is guided onto a specific area on a substrate by a magnetic field. Each such area overlaps the adjacent ones. Thus, a compositionally-graded thin film is deposited in the overlap area because of mixing of each deposited thin film from each APG that has a thickness grade. The deposited thin film is separated into 1,089 samples (the size of each is 1×1 mm2) using a grid on the substrate. The samples together are referred to as the thin film library. To demonstrate the capability of CAPD, two thin film libraries were deposited in this study. One is a thin film library of a PdCuSi alloy system, and the other is a MoZrPd system. The compositions and crystallinity of the samples were evaluated on the substrate using EDS and IP-XRD respectively. Analysis of the samples showed a graded composition, and some of the samples were shown to be amorphous in both libraries.