An intermediate-layer lithography method for generating multiple microstructures made of different conducting polymers

An intermediate-layer lithography (ILL) method has been developed in this work to generate multiple microstructures of different conducting polymers on the same substrate. Previous and current efforts in developing conducting polymer microsystems mainly focus on generating a device of a single function. When multiple micropatterns of different conducting polymers are produced on the same substrate, many microsystems of multiple functions can be envisioned. However, existing techniques present significant technical challenges of degradation, low throughput, low resolution, depth of field, and/or residual layer in producing conducting polymer microstructures. To circumvent these challenges, the ILL method has been explored to generate multiple micropatterns of different conducting polymers in a parallel manner. In this method, conducting polymer materials and a non-conducting polymer intermediate layer are first coated on a substrate, and are then patterned through a mold insertion at a raised temperature. In this work, the ILL has been used to successfully pattern three types of commonly used conducting polymers on the same substrate under a single mold insertion, and simulation has been conducted to gain a good understanding of the molding process. Due to distinctive advantages of simplicity, low cost and high throughput, the ILL has promising applications in fabricating micropatterns for polymer-based microsystems.     

Generation of micropatterns of conducting polymers and aluminum using an intermediate-layer lithography approach and some applications

Conducting polymers, because of their promising potential to replace silicon and metals in building devices, have attracted great attention since the discovery of high conductivity in doped polyacetylene in 1977. Lithographic techniques present significant technical challenges when working with conducting polymers. Sensitivity of conducting polymers to environmental conditions (e.g., air, oxygen, moisture, high temperature, and chemical solutions) makes current photolithographic methods unsuitable for patterning the conducting polymers due to the involvement of wet and/or dry etching processes in those methods. Existing non-photolithographic approaches have limitations in throughput, resolution, or electrical insulation. Therefore, an intermediate-layer lithography (ILL) approach has been recently developed by my group to produce conducting polymer micro/nanostructures. In the ILL method, an intermediate layer of an electrically insulating polymer is coated between the substrate and a layer of the conducting polymer to be printed. Subsequently, the conducting polymer is printed through mold insertion using a hot-embossing process. The current hot-embossing based methods face the obstacles of residual layer and depth of field (i.e., the height variation in the mold structures). In contrast, the ILL approach does not leave a residual layer in the material of interest, making conducting polymer patterns isolated from one another and avoiding the shorting problem in the electrical applications of these patterns. Furthermore, in the ILL, the height variation potentially existing among the mold structures has been transferred to the intermediate layer, ensuring that all patterns in the mold have been properly transferred to the conducting polymer layer. In addition to conducting polymers, the ILL can also be applied to pattern metals as well as other types of polymers. This paper gives a review of this ILL method and reports the results that we have achieved to date, including generation and applications of single and multiple layers of microstructures of conducting polymers and aluminum.     

多形状孔缝耦合分析及其实验研究

以平板孔缝耦合为典型对象,选取圆形、正方形、长方形孔形,建立了无限大平板的小孔耦合模型,然后利用矩量法对孔缝耦合模型进行求解分析,得到了表征电磁耦合强弱的能量传输系数。为验证方法的有效性,搭建了实验系统对不同的孔缝类型进行了测试。结果表明,电磁波通过不同形状孔缝耦合过去的能量和孔缝的面积以及电磁波的入射角度有密切的关系。     

导电聚合物及其在生物传感器构建中的应用

导电聚合物最重要的性质就是其导电性,它可以作为分子导线,使电子在生物分子与电极表面直接传递,显著提高生物传感器的响应、灵敏度和稳定性.主要介绍了导电聚合物的结构特征、基本性能、分类、研究现状、用途及其在传感器构建中的应用,并对导电聚合物在生物传感器中的发展趋势与应用前景进行了展望.     

共轭导电聚合物及其在传感器中的应用

分析了共轭导电聚合物的结构特征和导电机理，综述了共轭导电聚合物在离子传感器、气体传感器、湿度传感器和生物传感器中的应用和原理，并展望了共轭导电聚合物在传感器中的研究方向和应用前景。     

Ionic liquid as electrolyte in a self-powered controlled release system

Initial studies into the development of a self-powered controlled release system using ionic liquid electrolyte were performed via galvanic coupling of a conducting polymer doped with dye and a zinc anode. The conducting polymer employed was polypyrrole (PPy) doped with phenol red (PR) dye. The electrochemical properties of the polymer as well as the dye release process initiated by a Zn electrode were investigated. A bilayer conducting polymer structure wherein polypyrrole–polystyrene sulfonate (PPy-PSS) coated on top of PPy-PR ensured no leakage of dye, yet allowed efficient release of PR on galvanic coupling in a temperature sensitive electrolyte.     

Planate conducting polymer actuator based on polypyrrole and its application

In this study, we propose a planate actuator which can transform only its central part locally. We have developed a planate conducting polymer actuator based on polypyrrole (PPy) and two types of acids, such as p-phenol sulfonic acid and dodecylbenzene sulfonic acid, by electrodeposition. Its structure was patterned bimorph structure with anion-driven, cation-driven and bimorph layers. The planate conducting polymer actuator could deform only its central part locally. Moreover, we introduce a micro-pump that operates by planate conducting polymer actuator as the drive source. The water level in the flow channel of micro-pump shows the reciprocating motion measuring ±2 mm in accordance with the oscillation of the bimorph conducting polymer actuator which was approximately 28 μl/min. The oscillating volume can be controlled by the application of electrochemical potential and its scan rate applied to the actuator.     

Mixing and flow regulating by induced-charge electrokinetic flow in a microchannel with a pair of conducting triangle hurdles

The induced-charge electrokinetic flow (ICEKF) in a rectangular micorchannel with a pair of conducting triangle hurdles embedded in the middle is investigated in this paper. A correction method is suggested to numerically estimate the induced zeta potential on the conducting surface. Two-dimensional pressure-linked Navier-–Stokes equation is used to model the flow field in the channel. The numerical results show flow circulations generated from the induced non-uniform zeta potential distribution along the conducting hurdle surfaces. It is demonstrated numerically that the local flow circulations provide effective means to enhance the flow mixing between different solutions; by adjusting the electric field applied through the microchannel with a non-symmetric triangle hurdle pair, an electrokinetic flow regulating effect can be obtained and this effect depends on the dimensions of the conducting converging–diverging section. The mixing and flow regulating using ICEKF described in this paper can be used in various microfluidics and lab-on-a-chip (LOC) applications.     

导电聚合物生物传感器的研究进展

导电聚合物因其良好的导电性能,可作为分子导线使电子在生物活性物质与电极间直接传递,是构建生物传感器的一种新材料。主要讨论了导电聚合物生物传感器的构建、生物活性物质的固定化。简要地回顾了此类生物传感器在医学、食品工业和环境监测等领域中的应用。     

大尺寸导体目标的低频宽带散射测量与仿真

用扫频方法测量了缩比模型的低频宽带雷达散射截面,通过变换得到大尺寸导体目标的低频宽带RCS;并利用时域有限差分方法对全尺寸导体目标的雷达散射截面进行仿真计算,也得到了大尺寸的导体目标的低频宽带RCS;结果表明了这两种方法的一致性,为获得大尺寸导体目标的低频宽带散射特性提供了可以信赖的手段.     

Enhanced conductivity of aligned PANi/PEO/MWNT nanofibers by electrospinning

Conducting composite nanofibers were fabricated from a mixture of multiwalled carbon nanotubes (MWNTs) and a polyaniline (PANi)/poly(ethylene oxide) (PEO) blend using an electrospinning process. We observed a surprising transition in the electrical conductivity of the conducting composite nanofibers while measuring the I–V characteristics of the nanofibers aligned on an electrode when they were exposed to an applied high voltage. We believe that this unexpected transition is closely related to the self-heating of the MWNTs incorporated into the conducting polymer. This type of self-heating method will be very helpful in enhancing the electrical properties of nanoscale conducting composite fibers.     

Implementing single-scale wavelet transform processor with magnetostatic surface wave device

When the envelope of the conducting strips for the input transducer of magnetostatic surface wave(MSSW) device is designed according to the wavelet-function envelope,the impulse-response function of the input transducer for MSSW device is equal to the wavelet function,so that single-scale wavelet-transform processor of MSSW type is fabricated.First,according to the envelope function of the wavelet,the length function of the conducting strips is defined,then,the lengths of the conducting strips can be calcul...     

Identification of small flaws in conductors using magnetostatic measurements

The identification of small flaws in a conducting half-space or rectangular specimen using boundary measurements of the static magnetic field is considered. The perturbed magnetic field due to the presence of a small flaw is assumed to be generated by an equivalent current dipole located at the flaw position. Explicit formulas are given for the identification of a single flaw or a set of flaws in a conducting half-space or rectangular specimen.     

A program to compute EM scattering of plane wave by a perfectly conducting half-plane in a finitely conducting layered half-space

A FORTRAN program utilizing an integral equation calculates 10 field quantities relating to the electromagnetic (EM) scattering of plane wave by a perfectly conducting half-plane buried in a finitely conducting layered half-space. The computing algorithm is executable on a computer of small storage capacity such as PDP 11/40 and as such is useful to many exploration scientists without the facility of a mainframe computer, for computing model curves to interpret field data.     

Self-Supervised Music Motion Synchronization Learning for Music-Driven Conducting Motion Generation

The correlation between music and human motion has attracted widespread research attention. Although recent studies have successfully generated motion for singers, dancers, and musicians, few have explored motion generation for orchestral conductors. The generation of music-driven conducting motion should consider not only the basic music beats, but also mid-level music structures, high-level music semantic expressions, and hints for different parts of orchestras (strings, woodwind, etc.). However, most existing conducting motion generation methods rely heavily on human-designed rules, which significantly limits the quality of generated motion. Therefore, we propose a novel Music Motion Synchronized Generative Adversarial Network (M²S-GAN), which generates motions according to the automatically learned music representations. More specifically, M²S-GAN is a cross-modal generative network comprising four components: 1) a music encoder that encodes the music signal; 2) a generator that generates conducting motion from the music codes; 3) a motion encoder that encodes the motion; 4) a discriminator that differentiates the real and generated motions. These four components respectively imitate four key aspects of human conductors: understanding music, interpreting music, precision and elegance. The music and motion encoders are first jointly trained by a self-supervised contrastive loss, and can thus help to facilitate the music motion synchronization during the following adversarial learning process. To verify the effectiveness of our method, we construct a large-scale dataset, named ConductorMotion100, which consists of unprecedented 100 hours of conducting motion data. Extensive experiments on ConductorMotion100 demonstrate the effectiveness of M²S-GAN. Our proposed approach outperforms various comparison methods both quantitatively and qualitatively. Through visualization, we show that our approach can generate plausible, diverse, and music-synchronized conducting motion.     

Decreasing the dimension of a system of scalar equations in the solution of diffraction problems

A vector integral equation is constructed, and an algebraic representation of the equation is considered in the solution of a boundary-value problem in an ideally conducting polyhedron. Moreover, due to the introduction of local coordinate systems on each of the faces of the ideally conducting polyhedron, the integral vector equation relative to the three constituents of the surface current reduces to a system of two scalar integral equations relative to the corresponding components of the current, expressed in the local coordinate systems.     

Transparent electrodes based on conducting polymers for display applications

The materials science and engineering related to the fabrication of conducting polymer thin films and the progress in the development of devices integrated with organic transparent electrodes based on conducting polymers for display applications are reviewed. Transparent electrodes are essential components for many display modules. With the evolution of display technologies, conducting polymers are recently emerging as important alternative materials for the fabrication of transparent electrodes. Conducting polymers offer some advantages, such as light weight, low cost, mechanical flexibility and excellent compatibility with plastic substrates for the development of next-generation display technologies and, in particular, are expected to play an important role in the development of flexible display technologies.     

A systematic method for analyzing magnitude estimation data

Magnitude estimation is frequently used for measuring the strength of subjective sensation in ergonomics studies. Although the data obtained by magnitude estimation are easy to interpret, caution must be taken in both planning/conducting an experiment and analyzing the results. This study presents a systematic and generalized method for analyzing the magnitude estimation data. Critical considerations and recommendations are suggested in each stage of planning, conducting, and analyzing an experiment. An interactive software program (named MEDAS: Magnitude Estimation Data Analysis System) was developed which implemented the rules and procedures for analyzing the magnitude estimation data.

Relevance to industry

This study presents the rules and procedures for planning, conducting, and analyzing an ergonomics experiment using magnitude estimation. The results of this study can aid ergonomists in designing and evaluating product alternatives based on subjective data obtained by magnitude estimation.     

All-plastic distributed pressure sensors: taylor-made performance by electroactive materials design

A new technology of flexible all-plastic pressure sensors is developed using conducting polymers as electroactive materials on plastic substrates. The lithographically patterning of one of the conducting sheets being part of the device makes feasible the construction of a distributed pressure sensor giving not only the quantitative pressure information but also its spatial distribution. A response time as low as 2 ms, and a lifetime over 1 millions of actuations are obtained. The first demonstrators work in pressure ranges from 30 to 1,200 g/cm². These working pressure ranges can be adjusted, on the one hand by the proper spatial design of conducting and non-conducting paths; on the other hand, by the adequate design of the electroactive material in terms of conductivity, film morphology and composition. The present paper describes the development of an innovative, low cost and flexible technology opening interesting potential opportunities for high-surface applications.     

Postmortem reviews: purpose and approaches in software engineering

Conducting postmortems is a simple and practical method for organisational learning. Yet, not many companies have implemented such practices, and in a survey, few expressed satisfaction with how postmortems were conducted. In this article, we discuss the importance of postmortem reviews as a method for knowledge sharing in software projects, and give an overview of known such processes in the field of software engineering. In particular, we present three lightweight methods for conducting postmortems found in the literature, and discuss what criteria companies should use in defining their way of conducting postmortems.