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Natural enzymes are widely employed as powerful biocatalysts. However, their further application is limited by the intrinsic characteristics of enzymes. To overcome this drawback, nanomaterials with enzyme-mimicking performance (defined as nanozymes) have attracted tremendous attention in recent decades. To date, over 50 kinds of nanomaterials have been found to possess inherent enzyme-mimetic properties. Among these, metal–nitrogen–carbon (M-N-C) nanozymes are the most promising nanomaterials due to their satisfactory activity, tunable configuration and chemical stability. Consequently, it is of great research value to focus on progress in this field. In this review, we systematically summarize recent advances in M-N-C nanozymes with various enzyme-like properties, including peroxidase-like, oxidase-like, catalase-like, superoxide dismutase-like and multiple enzyme-like performances. Furthermore, strategies for regulating enzyme-like activity and substrate specificity are comprehensively highlighted at the atomic level. The introduction of heteroatoms, rational design of the coordination environment and engineering of M-N-C nanostructures are discussed by combining experimental investigations with theoretical explorations. These approaches can unveil the origins of and provide insights into the enzyme-like mechanisms. We also review recent progress with M-N-C nanozymes for sensing and biomedical applications. Finally, current challenges and future opportunities for the development of advantageous M-N-C nanozymes are also proposed. This review is expected to provide inspiration and guidelines for further research on the rational design of perfect nanozymes.

A hybrid passivation method a using parylene and silicon dioxide combination layer for a film-like organic light-emitting diode (OLED) was applied on a polycarbonate substrate. Parylene coating by vapor polymerization is a highly effective passivation process for the OLED, and it is applied to the entire top surface and the edges of the OLED device. To minimize the permeation of moisture and oxygen from the top surface of the device, an additional layer of silicon dioxide was deposited over the parylene-coated layer. It was found that the water vapor transmittance rate (WVTR) of parylene (15 µm in thickness)/SiO2 (0.3 µm in thickness) combination layers deposited on the polycarbonate film was decreased to less than 10-3 g/(m2d). The OLED that had undergone hybrid passivation showed significantly longer lifetime characteristics in ambient conditions than the non-passivated OLED. The lifetime of the passivated OLED was 400 h and it was more than ten times the lifetime of the conventional non-passivated OLED.

One of the main obstacles to including transient dynamic effects into the performance functions of a structural optimization for microelectromechanical systems (MEMS) is the high computational cost of each time-dependent response simulation. This paper focuses on the application of model order reduction techniques to optimal design so as to reduce the transient analysis time for the optimization process. To do this, our open-source software mor4ansys performs model order reductions via the block Arnoldi algorithm directly to ANSYS finite element models. We adopt a micro accelerometer as an example to demonstrate the advantages of this approach. The harmonic and transient results of a reduced-order model of the accelerometer yield very good agreement with that from the original high-dimensional ANSYS model. The use of reduced-order models within the optimization iterations produces almost the same results as those without model order reduction, and speeds up the total computation by at least an order of magnitude.

This paper discusses optimization of an electromagnetic microactuator for large-displacement optical switching. The microactuator used in this research is a laterally driven electromagnetic one that provides parallel actuation to the silicon substrate surface (in-plane motion) using the Lorentz force. When the microactuator is driven by the distributed Lorentz force induced along the arch-shaped leaf springs, a buckling phenomenon in two leaf springs enables a large displacement with a relatively small actuation load. An important design objective of a microactuator is to achieve a large displacement with a low actuating force. In this research, two optimization formulations have been performed to improve the displacement capabilities of the microactuator. In the first, the actuation load to obtain a specific displacement is minimized, subject to constraints on the first natural frequency and maximum allowable stress. In the second, the actuation displacement for a given actuation load is maximized, subject to the same constraints as in the first formulation. These optimizations have generated considerably improved designs, making the actuators capable of large-displacement actuations with small actuating loads.

Admittance or impedance spectroscopy is one of the powerful tools to study the equivalent circuit models and the dielectric relaxation processes in organic and inorganic materials and devices. The frequency-dependent properties of small molecule-based organic light emitting diodes have been studied. The single-layer diodes can be modeled as a simple parallel resistor–capacitor circuit. The equivalent circuit models of double-layer devices, for which the single-layer device model is expanded and the interface properties between the organic layers are included, are suggested.

In this study, we investigated the basic mechanical properties of indium–tin–oxide (ITO) films on polymer substrates which are exposed to externally inducing bending force. By using the Storney formula including the triple layer structure and bulge tests for measuring the conductive changes of patterned ITO islands as a function of bending curvature, the mechanical stability of ITO films on polymer substrates was intensively investigated. Numerical analyses and experimental results show that externally induced mechanical stress in the films depends on substrate material and its thickness, respectively. Therefore, an organic buffer layer was employed to improve the mechanical stability of ITO films, and then, the effects of the buffer layer were quantified in terms of conductivity–strain variations. As a result, it is found that a buffer layer is also a critical factor for determining the magnitude of mechanical stress and that the layer with Young's modulus lower than the specified value can contribute to relieving the mechanical stress of the films.

In this paper we present an in-depth parametric study and structural optimization for a micro-optical switch based on the concept of a laterally driven electromagnetic microactuator (LaDEM). This utilizes the nonlinear behavior of a snap-through buckling occurring in two arch-shaped leaf springs of the switch, when actuated by a distributed Lorentz force induced along the leaf springs. A sudden jump in displacement can facilitate a large actuation stroke suitable for practical applications. The leaf springs are connected to the fixed frame with two meandering parts, which also enhance their flexibility. Thus, an important objective in the design of the micro-optical switch is to achieve a large displacement with low actuation force. For this purpose, the effect of important geometrical parameters, such as the initial height of the leaf spring and the dimensions of meandering part on the displacement response is first investigated and optimized to satisfy given design specifications. The nonlinear displacement–load response calculated by a modified Riks method in ABAQUS shows good agreement with the measurement result. Nonlinear finite element techniques and optimizations are found to be valuable tools for the analysis and design of microactuators, which utilize a complex nonlinear snap-through buckling behavior.

High-performance metal–insulator–metal (MIM) devices on flexible polymer substrates were successfully fabricated without any defects such as cracks, delamination and blistering. This work examines the mechanical and electrical properties of MIM devices constructed using anodic Ta2O5 films. Using newly developed methods including stepped heating process and low-temperature post-annealing below 180°C, we obtained high-performances MIM devices on polymer substrates. Here, we propose the use of stacked bottom electrode and water barrier layer in order to enhance the ductility of the Ta electrode and to prevent blistering problems, respectively. Rutherford backscattering spectroscopy (RBS), auger electron spectroscopy (AES) and transmission electronic microscope (TEM) observations were performed for the structural investigation of the MIM devices on polymer substrates. Electrical measurements were also carried out for as-deposited and thermally treated MIM devices including Al/Ta/Ta2O5/Cr or Ti structures. They exhibit a low leakage current (below 10-7 A/cm2 at 2 MV) and reasonable breakdown voltage (5–7 MV/cm) with a uniformity of 92%. Finally, under low-temperature post-annealing conditions, The Current–Voltage (I–V) behaviors and conduction mechanisms of MIM devices on polymer substrates are discussed based on the results of electrical measurements, structural investigations and conduction band modeling.

A robust optimal design of shape and size is formulated for vibratory microgyroscopes that can reduce the effect of variations from uncertainties in microelectromechanical systems fabrication. The important objective in the design of vibratory microgyroscopes is to reduce the difference between the resonance frequencies of the vertical (detecting) and lateral (driving) modes in order to attain high mechanical detecting sensitivity. The deterministic optimization for this goal results in good performance but is sensitive to fabrication errors. The basic idea of the present formulation is to obtain robustness of the objective function by minimizing the gradient of the objective function with respect to uncertain variables through a proper selection of shapes and sizes. The beam width, length and thickness of vibratory microgyroscopes are adopted as design variables and are simultaneously regarded as uncertain variables in the optimization problems. A robustness check using a newly defined yield through the Monte Carlo simulation has shown that the robust optimal design obtained has generated twice the number of acceptable designs than the deterministic optimum. The important point is that the formulation of minimizing the maximum sensitivity of the objective function requires no statistical information on the uncertainties and yet achieves robustness.

We have developed a novel encapsulation method for flexible organic light-emitting diodes (OLEDs) using poly(dimethylsiloxane) (PDMS). The new method, which uses polycarbonate film, silicon dioxide, and PDMS, was found to enhance the lifetime of OLEDs in air. Optical measurements of the preservation of calcium films encapsulated with PDMS showed that the water and oxygen permeation rates of the PDMS encapsulation were reduced from a level of 0.57 g m-2 d-1 (bare substrate) to 1×10-7 g m-2 d-1. These results indicate that the PDMS barrier coatings have a good potential for flexible OLED applications.

It is essential to align masks without tolerance in every deposition step when fabricating thin-film transistors (TFTs) on a polymer substrate. However, the shrinkage of the polymer substrate due to thermal effect may arise during the deposition process. We observed the variation of shrinkage as a function of the annealing temperature. It was found that the substrates keep shrinking up to a critical temperature and stay the same above that point. The thermal treatment was conducted on substrates polycarbonate (PC), the polyarylate (PAR), and poly(ether sulfone) (PES). After predeposition annealing, the shrinkage was prevented but deformation was observed on the surface. An inorganic thin film with a different thermal expansion coefficient was employed to remove the deformation and this resulted in the elimination of strain.

Nematic liquid crystal (NLC) alignment effects on SiNx thin film layers treated by ion-beam irradiation for three types of N ratio were successfully studied for the first time. The SiNx thin film was deposited by plasma-enhanced chemical vapor deposition using three types of N ratio. To characterize the film, atomic force microscopy was performed. Good LC aligning capabilities on the SiNx thin film treated by ion-beam irradiation for all N ratios can be achieved. The low pretilt angle for an NLC on the SiNx thin film treated by ion-beam irradiation was observed and could be adopted in planar alignment liquid crystal display applications as in-plane switching and fringe-field switching modes.

We have studied the liquid crystal (LC) alignment and tilt angle generation of a nematic liquid crystal (NLC) on a homeotropic polyimide (PI) surface using a new ion beam source. The tilt angle of the NLC on the homeotropic PI surface for all incident angles is about 38° and this angle has a stabilization trend. A good LC alignment of the NLC on the homeotropic PI surface by to exposure ion beam of 45° incidence angle was observed. Also, the tilt angle of the NLC on the homeotropic PI surface by to exposure ion beam of 45° incidence angle had a tendency to decrease as ion beam energy density increased. Thus, we demonstrated that the tilt angle could be controlled from vertical to horizontal directions. Also, the alignment character of the NLC on the homeotropic PI surface with respect to ion beam energy was good at more than 1500 eV. Finally, a superior LC alignment thermal stability on the homeotropic PI surface subject to ion beam exposure was achieved.

The nematic liquid crystal (NLC) alignment capability achieved by ion beam alignment on a nitrogen-doped diamond-like carbon (NDLC) thin film was investigated. To characterize the NDLC thin film, we analyzed the obtained atomic force microscopy (AFM) images and pretilt angle. Moreover, we investigated the electro optical (EO) performance characteristics of ion-beam-aligned in-plane switching (IPS) cell with the NDLC thin film. The EO performance characteristics of the ion-beam-aligned IPS cell were observed by ion beam exposure on the NDLC thin film and compared with those of a rubbing aligned polyimide (PI) thin film. Finally, similarly prominent capacitance–voltage (C–V) characteristics were achieved in the ion-beam-aligned NDLC thin film compared with the rubbing-aligned PI thin film.

We investigate the details of the precessional motion of the magnetic moment in canted antiferromagnetic YFeO3, which is excited by a linearly polarized terahertz (THz) pulse at room temperature. By tuning the spectral component of the input THz pulse around the quasi-ferromagnetic mode located near 0.3 THz, we have experimentally clarified the resonance effect in the THz control of the spin state. We were able to confirm this result from the simulation based on the Landau–Lifshitz–Gilbert equation with the two sub-lattice model for the canted antiferromagnet. Finally, we discuss a crossover from a linear to a nonlinear magnetic response to the input THz pulse during the THz-induced precessional switching of the magnetization.

In this study, solution-processed transparent conductors on flexible glass substrate were investigated using indium–tin-oxide (ITO) nanoparticle (NP) ink. The ITO-NP conductors were well fabricated on the flexible glass substrate with neither distortion nor deformation. Optical transmittances of the ITO-NP conductors on flexible glass substrate were enhanced to more than 91% that is higher than those on rigid glass substrate owing to decreased thickness. As well, the ITO-NP conductors on flexible glass substrate heat-treated at 500 and 600 °C showed good thermal stabilities of electrical and optical properties. In case of bending characteristics of samples heat-treated at 500 and 600 °C, the change in resistance was slight within 14%, which is smaller than those of conventional TCOs on flexible films. Based on the results, we propose that the solution-processed ITO-NP conductors are suitable for TCOs on flexible glass substrates.

Lead-free piezoelectric 0.06(LiNbO3)–0.94(Na0.5K0.5)NbO3 (LNKN) ceramics in disc form were fabricated and characterized to acquire good electromechanical properties. A molding method including cold isostatic pressing (CIP) was used to form a dense and regular microstructure and suppress the cracking problems of LNKN ceramics during the following high-temperature sintering. The LNKN ceramic sintered at 1040 °C showed a high piezoelectric constant d 33 of 170 pC/N owing to its high density. Furthermore, perovskite LNKN films with the same composition as the ceramics were fabricated using 2-methoxyethanol-based sol–gel solution. The sol–gel surface coating on the LNKN ceramics was found to be very effective for increasing the piezoelectric constant because of the interface stabilization effect leading to a uniform electric field in piezoelectric elements. As a result, we obtained the highest piezoelectric constant d 33 of 183 pC/N. The lead-free LNKN ceramics are promising for applications in eco-friendly ferroelectric and piezoelectric devices.

We report high-performance ink-jet-printed 2,8-difluoro-5,11-bis(triethylsilylethynyl) anthradithiophene (diF-TESADT) organic thin-film transistors (OTFTs) facilitated by polymer blending. The film morphology and crystal structure of diF-TESADT films were greatly improved by printing on a predeposited poly(α-methyl styrene) (PαMS) layer possibly due to the confined droplet area and thus increased intermolecular interactions. Additionally, partial dewetting and the formation of irregular film shapes were effectively controlled resulting in uniform and improved device performance in the predeposited blending system. Through a proper optimization of printing parameters such as substrate temperature and processing solvent, diF-TESADT TFTs with an average field-effect mobility of 0.34±0.13 cm2 V-1 s-1 (max 0.64 cm2 V-1 s-1) and subthreshold slope of 0.456±0.090 V decade-1 have been achieved.

Enhanced stability of all solution-processed organic thin-film transistors (OTFTs) has been achieved by replacing metallic electrodes with glycerol-modified poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) polymer electrodes. The modified PEDOT:PSS showed a substantially low electrical resistivity of 6.4×10-3 Ω cm with improved environmental stability and water-resistant characteristics, which are crucial for highly reliable applications. Additionally, the modified PEDOT:PSS electrodes were highly stable under intense mechanical stress, allowing their application to flexible electronics. Particularly, all solution-processed flexible and transparent OTFTs with the modified PEDOT:PSS electrodes showed a field-effect mobility decrease of only 2.7% after a tensile mode mechanical fatigue test, while OTFTs with metallic electrodes showed a mobility decrease of 56.6% under identical test conditions.

Semitransparent bulk-heterojunction organic photovoltaics with power conversion efficiency (PCE) of 1.63±0.39% was achieved by using poly(3-hexylthiophene) (P3HT)/phenyl-C61-butyric acid methyl ester (PCBM) active layer and Ag/Ca/Ag transparent cathode. Insertion of a thin Ag interfacial layer (1 nm) between the P3HT/PCBM active layer and Ca/Ag transparent cathode dramatically improved the PCE from 0.83±0.33 to 1.63±0.39% as well as other photovoltaic properties such as fill factor, short-circuit current, and series resistance. In this experiment, it is considered that the improved device performance is possibly due to improved contact property by the Ag interfacial layer at the active/cathode interface.

In this paper, we describe the formation of vertically aligned liquid crystal molecules on TiO2 films treated by ion-beam (IB) irradiation. Regular or irregular pretilt angles were achieved as a function of IB incident angle. Uniform alignment was obtained only at an incident angle of 45°. The contact angle, which is related to the surface energy, was measured to confirm the tendency of variation in the pretilt angle. In addition, the weak anchoring energy of LC molecules on IB-irradiated TiO2 was ascertained by the thermal stability at low temperature.

We demonstrated the annealing effects displayed by liquid crystal antiparallel cells made from ion beam-irradiated blended polyimide layers. The pretilt angles of the liquid crystals after annealing at 90 °C for 10 min were similar to those before annealing, which demonstrates good thermal stability for liquid crystal antiparallel cells. Contact angle increases as vertical polyimide concentration increases, a trend that corresponds closely to the variation in pretilt angle. Uniform liquid crystal alignment was observed from a photomicrograph. Strong anchoring energies allowed the liquid crystal to maintain homeostasis and withstand thermal stress.

Generally, liquid crystal (LC) orientation on rubbed polystyrene (PS) surfaces runs in the direction orthogonal to the rubbing process. In this study, homogeneous LC orientations were produced in the direction parallel to the ion beam (IB) process on PS surfaces using various IB exposure energies. Through x-ray photoelectron spectroscopy it was shown that IB irradiation resulted in the reformation of O=C bonds resulting from surface oxidation or charge transfer, reversely tracing out the produced pretilt angles of the homogeneous LC. Moreover, thermal tests on IB-irradiated PS surfaces were carried out which showed that a relatively high IB exposure energy induced a thermally stable LC alignment property. Finally, we determined the mechanism by which homogeneous LCs are aligned on IB-irradiated PS surfaces with electro-optical properties of twisted-nematic LC cells.

SiO2thin film has a wide range of applications, including insulation layers in microelectronic devices, such as semiconductors and flat panel displays, due to its advantageous characteristics. Herein, we developed a new eco-friendly method for manufacturing SiO2nanoparticles and, thereby, SiO2paste to be used in the digital printing process for the fabrication of SiO2film. By excluding harmful Cl-and NO3-elements from the SiO2nanoparticle synthetic process, we were able to lower the heat treatment temperature for the SiO2precursor from 600 to 300 °C and the diameter of the final SiO2nanoparticles to about 14 nm. The synthesized SiO2nanoparticles were dispersed in an organic solvent with additives to make a SiO2paste for feasibility testing. The SiO2paste was printed onto a glass substrate to test the feasibility of using it for digital printing. The insulation resistance of the printed film was high enough for it to be used as an insulation layer for passivation.

The dipole–dipole interaction between liquid crystals (LCs) and a polystyrene (PS) surface induced by ion beam (IB) irradiation was successfully studied. The LC molecular orientation follows the IB alignment direction on the PS surface, upon IB irradiation or rubbing. The LC orientation on the PS surface is fixed by IB irradiation and is not affected by rubbing. Also, the LC alignment direction depends strongly on the C=O bonds formed from the C=C and C–C bonds on the PS surface that are broken by the IB irradiation. The LC alignment induced by IB irradiation on the PS surface using dipole–dipole interaction between the LCs and the PS surface is more strongly affected by the chemical bonding of broken chains than by physical processes such as the microgroove effect and π–π interaction. Furthermore, the anchoring strength of LCs on the PS surface upon IB irradiation is stronger than that of the PS surface upon rubbing as indicated by the LC orientation direction.

We investigated the effect of annealing treatment and surface morphology on power conversion efficiency (PCE) of organic photovoltaic (OPV) devices. The bulk-heterojunction OPV devices were fabricated by using poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) as a donor and an acceptor material, respectively. Significant changes of surface morphology and grain size were observed by varying annealing temperature, which is possibly due to different diffusion rate of PCBM molecules into the bulk-heterojunction polymer films. From these results, we conclude that differences in surface morphology and grain size are responsible for the significantly different PCE in the OPV devices. Consequently, the PCE is improved from 0.5 to 2.6% combined with the increase of short-circuit current and fill factor by annealing treatment at 150 °C.

We report all solution-processed high-resolution bottom-contact indium-gallium-zinc-oxide (IGZO) thin film transistors (TFTs) using a simple surface patterning and dip-casting process. High-resolution nanoparticulate Ag source/drain electrodes and a sol?gel processed IGZO semiconductor were deposited by a simple dip-casting along with a photoresist-free, non-relief-pattern lithographic process. The deposited Ag and IGZO solution can be steered into the desired hydrophilic areas by a low surface energy self-assembled monolayer, resulting in source/drain electrodes and semiconducting layer, respectively. The all solution-processed bottom-contact IGZO TFTs including a channel length of 10??m typically showed a mobility range 0.05?0.2?cm2?V?1?s?1 with an on/off ratio of more than 106.

We investigated the electrical properties of triisopropylsilyl (TIPS)–pentacene organic thin film transistors (OTFTs) fabricated with a photoreactive polymer. The OTFTs fabricated with annealing of the gate dielectric layer had a field-effect mobility of up to 0.06 cm2 V-1 s-1, while those treated with ultraviolet (UV) irradiation showed a field effect mobility of 0.12 cm2 V-1 s-1. The large improvement in TIPS–pentacene OTFT performance using a photoreactive dielectric layer is probably due to the enhanced alignment of TIPS–pentacene molecules and improved dielectric properties.

The electrical properties of a split-gate-type flash cell are investigated and optimized by junction engineering to obtain a high reliability. Phosphorus implantation is conducted to form a cell source junction, and the following three different anneal conditions change voltage coupling ratio between the source and the floating gate. As the ratio increases, it is observed that program characteristic is improved and endurance property is degraded, which matches well with simulation result. Therefore, cells in the pure N2 group are considered to be optimized cells. Optimized cells guarantee 105 cycle endurance, and show excellent program disturbance and bake retention properties.

In this paper, the thermal behavior of SnO2–5 wt % Pd composite nanoparticles fabricated by an in-situ synthetic method was characterized. The in-situ synthetic method made the composite nanoparticles in one process, which is different from the current method in which Pd catalyst doping is separated from the synthetic process for SnO2. Tin and palladium organic reagents were used for the in-situ synthesis. These materials enable low-temperature processing since the removal of organic components is possible below 300°C. High resolution transmission electron microscope (HRTEM) observation revealed that the size of the synthesized particles ranged from 2 to 7 nm and that the Pd catalyst is uniformly distributed in the lattice of the SnO2 particles. In fact, X-ray diffraction (XRD) analysis certifies a uniform solid solution of the Pd catalyst in SnO2 since a prominent Pd peak was not found. The specific surface area of the synthesized particles measured with a Brunauer–Emmett–Teller (BET) surface analyzer exceeded 100 m2/g. The SnO2–5 wt % Pd composite nanoparticles also exhibit an excellent sensitivity of 0.62, which is defined as a ratio of R 3500/R 1000, after aging at 400°C for 5 h. Thus, ultrafine SnO2–Pd composite nanoparticles can be synthesized by the in-situ synthetic method.

Color tracking in a fringe-field driven homogenously aligned nematic liquid crystal cell [named fringe-field switching (FFS)] has been investigated. In the in-plane switching (IPS) device and the FFS device using liquid crystals (LCs) with negative dielectric anisotropy (-LC), the LCs rotate almost in plane except for surfaces where the color tracking occurs for cell retardation value that shows a maximal transmittance. In the IPS device, authentic color appears at a very low cell retardation value that exhibits a low transmittance and bluish white. However, the FFS device shows authentic color even at a relatively high cell retardation value 0.30 µm so that high transmittance and greenish white are kept.

In this paper, we investigated the position-dependent stress distribution of indium–tin–oxide (ITO) film on a polycarbonate (PC) substrate by applying an external bending force. It was found that crack density is maximum at the center position and decreases toward the edge. In accordance with crack distribution, it was observed that the change is electrical resistivity of ITO islands is maximum at the center and decreases toward the edge. From the result that crack density increases at the same island position as face-plate distance (L) decreases, it is evident that more stress is imposed on the same island position as L decreases.

We have investigated the properties of the surface plasmon resonance (SPR) spectra obtained by scanning each spot of protein arrays using a wavelength interrogation-based SPR sensor (custom-made). The surface structure of each protein array consists of glass/metal/proteins/air (ex situ). The analysis of serial spectra showed marked increases in SPR intensity and wavelength at the boundary area of protein array spots, which were mainly caused by the background signal from the glass substrate. However, at the central area, protein interaction caused an increase in SPR wavelength, and a decrease in SPR intensity. There was no significant difference between the central and boundary areas in terms of the roughness and thickness of the gold film. These results suggest that SPR intensity is a good indicator for distinguishing psuedosignals from real signals of biospecific interactions in the analysis of protein arrays using wavelength interrogation-based SPR sensors.

Reliable interconnection of electrodes to the plastic-based display with anisotropic conductive films (ACFs), of which the conductive particles were similar in elasticity to the substrates, was accomplished. The contact resistance value was maintained even while the junction was stressed under sudden changes in temperature and pressure. It was found that the conduction failure was caused by the action of a complex mechanism on the changes of a joint structure. The major driving factor seems likely to be defects in the transparent electrodes due to the thermal strain of substrates and penetration of conductive particles. Conductive particles with elasticity similar to that of the plastic substrates did little damage to the transparent electrodes on the substrates, and low temperature and pressure under a stepped process did not bring about their deformation either. As a result, a highly reliable interconnect with a very low contact resistance was realized.

In the solder bump chip on glass process, for the connection of the driver chip to Al pad on the glass substrate, the process of the electroless plating was developed to coat Ni on Al/photoresist system. It is necessary to pretreat Al surface to remove the oxide layer before the plating. In order to find the pretreatment process which does not damage photoresist or the substrate glass, the alkaline and fluoridic zincate processes have been investigated. Because the photoresist and Al thin film could be easily dissolved in the alkaline solution, it was considered that the fluoridic zincate process was a suitable one. After immersion in the zincate solution containing 1.5 g/ l NH4HF2 and 100 g/ l ZnSO4, electroless Ni plating was performed well. The additives in the zincate solution and thiourea in the plating solution enhanced the flatness of deposited surface. Acid dip improved the uniformity of the surface.