Scaling Up ITO‐Free Solar Cells

Indium‐tin‐oxide‐free (ITO‐free) polymer solar cells with composite electrodes containing current‐collecting grids and a semitransparent poly(3,4‐ethylenedioxythiophene):polystyrenesulfonate) (PEDOT:PSS) conductor are demonstrated. The up‐scaling of the length of the solar cell from 1 to 6 cm and the effect of the grid line resistance are explored for a series of devices. Laser‐beam‐induced current (LBIC) mapping is used for quality control of the devices. A theoretical modeling study is presented that enables the identification of the most rational cell dimension for the grids with different resistances. The performance of ITO‐free organic solar cells with different dimensions and different electrode resistances are evaluated for different light intensities. The current generation and electric potential distribution are found to not be uniformly distributed in large‐area devices at simulated 1 Sun illumination. The generated current uniformity increases with decreasing light intensities.     

直接心室辅助致动方法的现状与发展

直接心室辅助通过在心脏外侧柔性挤压心脏，帮助虚弱的心脏恢复功能。它能够避免人工器件与血液接触引发的血栓、血感染等问题，是人工心脏辅助器件研究与开发的重要领域之一。直接心室辅助的致动器，决定了器件的结构、形状、及其性能，是整个辅助器件关键中的关键，致动器上的任何突破有可能对直接心室辅助器件产生革命性影响。因此，本文从致动原理的角度，分析、探讨了直接心室辅助的致动方法及其存在问题，这对探索与开发满足要求的下一代直接心室辅助致动器有一定的帮助作用。     

Odour sampling 1: Physical chemistry considerations

The selection of an odour sampling device may influence the composition of the resulting odour sample. Limited comparison of emission rates derived from turbulent and essentially quiescent sampling devices confirms that the emission rates derived from these devices are quite different. There is therefore compelling evidence that current odour sampling practice should have greater regard for fundamental physical and chemical principles, the nature of the odour source and the conditions created by the sampling device. Such consideration may identify the most appropriate situations under which the use of these devices may or may not be correct.     

Reuse of permanent cardiac pacemakers.

Cardiac pacemakers are part of a growing group of expensive implantable electronic devices; hospitals in which 100 pacemakers are implanted per year must budget over $300 000 for these devices. This cost represents a considerable burden to health care resources. Since the "life-span" of modern pacemakers often exceeds that of the patients who receive them, the recovery and reuse of these devices seems logical. Pacemakers can be resterilized and tested with current hospital procedures. Reuse should be acceptable under Canadian law, but the manner in which the pacemakers are recovered and the patients selected should follow careful guidelines. Every patient should provide written informed consent before receiving a recovered pacemaker. Properly executed, reuse of pacemakers should provide a high level of health care while maintaining or reducing the cost of these devices.     

A decentralized clustering scheme for transparent mode devices

Clustering multiple devices to form a single powerful device is a common method for improving performance. Most designs of the clustering schemes in the current literature are deploying a traffic splitter in front of devices in the cluster which acts as a centralized job dispatcher splitting workloads to backend devices. In this paper, we propose a decentralized clustering scheme, with no traffic splitter deployed, as an alternative solution on building a cluster system for those devices configured in transparent mode, such as bandwidth controllers, NIPSs, and traffic monitors. Devices in the cluster process the network traffic in parallel in a decentralized manner to scale the throughput. A device can also migrate its workload to others for the purpose of load balance or fault tolerance. Experiment results suggest that the proposed scheme can effectively improve performance of transparent mode devices in terms of throughput, load balance, and fault tolerance.     

Bead-based microfluidic immunoassays: the next generation

Microfluidic devices possess many advantages like high throughput, short analysis time, small volume and high sensitivity that fulfill all the important criteria of an immunoassay used for clinical diagnoses, environmental analyses and biochemical studies. These devices can be made from a few different materials, with polymers presently emerging as the most popular choice. Other than being optically clear, non-toxic and cheap, polymers can also be easily fabricated with a variety of techniques. In addition, there are many polymer surface modification methods available to improve the efficiency of these devices. Unfortunately, current microfluidic immunoassays have limited multiplexing capability compared to flow cytometric assays. Flow cytometry employ the use of encoded microbeads in contrast with normal or paramagnetic microbeads applied in current microfluidic devices. The encoded microbead is the key in providing multiplexing capability to the assay by allowing multi-analyte analysis. Using several unique sets of code, different analytes can be detected in a single assay by tracing the identity of individual beads. The same principle could be applied to microfluidic immunoassays in order to retain all the advantages of a fluidic device and significantly improve multiplexing capability.     

Fast Charging Materials for High Power Applications

An overview of fast charging materials for high power applications is given. The behavior at high current density of several anodic and cathodic materials that have been utilized in lithium‐, sodium‐, and potassium‐ion batteries is considered. Furthermore, the behavior of capacitive and pseudocapacitive materials suitable for electrochemical capacitors and, also, of those that have been utilized for the realization of hybrid‐ion capacitors, which are nowadays an interesting reality in the field of high power devices, is discussed. The advantages and limitations of all these materials are critically analyzed with the aim of understanding their impact on real devices. On the basis of this analysis, the most important aspects are identified, which should be addressed in the future for the realization of advanced high power devices.     

Cardiac Pacing and Defibrillation in Children and Young Adults

The population of children and young adults requiring a cardiac pacing device has been consistently increasing. The current generation of devices are small with a longer battery life, programming capabilities that can cater to the demands of the young patients and ability to treat brady and tachyarrhythmias as well as heart failure. This has increased the scope and clinical indications of using these devices. As patients with congenital heart disease (CHD) comprise majority of these patients requiring devices, the knowledge of indications, pacing leads and devices, anatomical variations and the technical skills required are different than that required in the adult population. In this review we attempt to discuss these specific points in detail to improve the understanding of cardiac pacing in children and young adults.     

Feasibility of using bernstein modes for current drive in toroidal devices

The feasibility of using Bernstein modes for producing electron cyclotron current drive in toroidal devices is examined. It is shown that the negative role of trapped particles may reduce upon increasing the longitudinal slowing-down factor of waves. Numerical geometrical-optics calculations of the propagation and absorption of waves were performed for the scheme in which radiation is launched from the low-field side as an ordinary wave, linearly converted into an extraordinary wave, and finally converted into Bernstein mode. An analysis is performed for medium-sized toroidal devices. Based on numerical simulation, the parameters determining the efficiency of current drive, namely, the characteristic values of the resonant energies and the longitudinal slowing-down factor of waves in the region where most of the microwave power dissipates, are found.     

Paper-based point-of-care testing for diagnosis of dengue infections

Dengue endemic is a serious healthcare concern in tropical and subtropical countries. Although well-established laboratory tests can provide early diagnosis of acute dengue infections, access to these tests is limited in developing countries, presenting an urgent need to develop simple, rapid, and robust diagnostic tools. Point-of-care (POC) devices, particularly paper-based POC devices, are typically rapid, cost-effective and user-friendly, and they can be used as diagnostic tools for the prompt diagnosis of dengue at POC settings. Here, we review the importance of rapid dengue diagnosis, current dengue diagnostic methods, and the development of paper-based POC devices for diagnosis of dengue infections at the POC.     

Tissue culture on a chip: Developmental biology applications of self‐organized capillary networks in microfluidic devices

Organ culture systems are used to elucidate the mechanisms of pattern formation in developmental biology. Various organ culture techniques have been used, but the lack of microcirculation in such cultures impedes the long‐term maintenance of larger tissues. Recent advances in microfluidic devices now enable us to utilize self‐organized perfusable capillary networks in organ cultures. In this review, we will overview past approaches to organ culture and current technical advances in microfluidic devices, and discuss possible applications of microfluidics towards the study of developmental biology.     

An Ultrathin Flexible Single‐Electrode Triboelectric‐Nanogenerator for Mechanical Energy Harvesting and Instantaneous Force Sensing

The trends in miniaturization of electronic devices give rise to the attention of energy harvesting technologies that gathers tiny wattages of power. Here this study demonstrates an ultrathin flexible single electrode triboelectric nanogenerator (S‐TENG) which not only could harvest mechanical energy from human movements and ambient sources, but also could sense instantaneous force without extra energy. The S‐TENG, which features an extremely simple structure, has an average output current of 78 μA, lightening up at least 70 LEDs (light‐emitting diode). Even tapped by bare finger, it exhibits an output current of 1 μA. The detection sensitivity for instantaneous force sensing is about 0.947 μA MPa^?1. Performances of the device are also systematically investigated under various motion types, press force, and triboelectric materials. The S‐TENG has great application prospects in sustainable wearable devices, sustainable medical devices, and smart wireless sensor networks owning to its thinness, light weight, energy harvesting, and sensing capacities.     

Native and artificial forisomes: functions and applications

Forisomes are remarkable protein bodies found exclusively in the phloem of the Fabaceae. When the phloem is wounded, forisomes are converted from a condensed to a dispersed state in an ATP-independent reaction triggered by Ca²⁺, thereby plugging the sieve tubes and preventing the loss of photoassimilates. Potentially, forisomes are ideal biomaterials for technical devices because the conformational changes can be replicated in vitro and are fully reversible over a large number of cycles. However, the development of technical devices based on forisomes has been hampered by the laborious and time-consuming process of purifying native forisomes from plants. More recently, the problem has been overcome by the production of recombinant artificial forisomes. This is a milestone in the development of forisome-based devices, not only because large quantities of homogeneous forisomes can be produced on demand, but also because their properties can be tailored for particular applications. In this review, we discuss the physical and molecular properties of native and artificial forisomes, focusing on their current applications in technical devices and potential developments in the future.     

Programmable Nanocarbon‐Based Architectures for Flexible Supercapacitors

Supercapacitors (SCs), also called electrochemical capacitors, often show high power density, excellent charge/discharge rates, and long cycle life. The recent development of flexible and wearable electronic devices requires that their power sources be sufficiently compact and flexible to match these electronic components. Therefore, flexible SCs have attracted much attention to power current advanced electronics that can be flexible and wearable. In the past several years, many different strategies have been developed to programmably construct different nanocarbon materials into bendable electrode architectures. Furthermore, flexible SC devices with simplified configurations have also been designed based on these nanocarbon‐based architectures. Here, recent developments in the programmable assembly of bendable architectures based on nanocarbon materials are presented. Additionally, the design of flexible nanocarbon‐based SC devices with various configurations is highlighted. The progress made recently paves the way for further development of nanocarbon architectures and corresponding flexible SC devices. Future development and prospects in this area are also analyzed.     

Enabling personalized implant and controllable biosystem development through 3D printing

The impact of additive manufacturing in our lives has been increasing constantly. One of the frontiers in this change is the medical devices. 3D printing technologies not only enable the personalization of implantable devices with respect to patient-specific anatomy, pathology and biomechanical properties but they also provide new opportunities in related areas such as surgical education, minimally invasive diagnosis, medical research and disease models. In this review, we cover the recent clinical applications of 3D printing with a particular focus on implantable devices. The current technical bottlenecks in 3D printing in view of the needs in clinical applications are explained and recent advances to overcome these challenges are presented. 3D printing with cells (bioprinting); an exciting subfield of 3D printing, is covered in the context of tissue engineering and regenerative medicine and current developments in bioinks are discussed. Also emerging applications of bioprinting beyond health, such as biorobotics and soft robotics, are introduced. As the technical challenges related to printing rate, precision and cost are steadily being solved, it can be envisioned that 3D printers will become common on-site instruments in medical practice with the possibility of custom-made, on-demand implants and, eventually, tissue engineered organs with active parts developed with biorobotics techniques.     

Affinity separations using microfabricated microfluidic devices:<Emphasis Type="Italic">In situ</Emphasis> photopolymerization and use in protein separations

The use of microfabricated microfluidic devices offers significant advantages over current technologies including fast analysis time and small reagent requirements. In the context of proteomic research, the possibility of using affinity-based separations for prefractionation of samples using microfluidic devices has significant potential. We demonstrate the use of microscale devices to achieve affinity separations of proteins using a device fabricated from borosilicate glass wafers. Photolithography and wet etching are used to pattern individual glass wafers and the wafers are fusion bonded at 650°C to obtain enclosed channels. A polymer has been successfully polymerizedin situ and used either as a frit for packing beads or, when derivatized with Cibacron Blue 3GA, as a separation matrix. Both of these technologies are based onin situ UV photopolymerization of glycidyl methacrylate (GMA) and trimethylolpropane trimethacrylate (TRIM) in channels.     

Assessment of albumin removal from an immunoaffinity spin column: Critical implications for proteomic examination of the albuminome and albumin‐depleted samples

High abundance proteins in serum and plasma (e.g., albumin) are routinely removed during proteomic sample processing as they can mask lower abundance proteins and peptides of biological/clinical interest. A common method of albumin depletion is based on immunoaffinity capture, and many immunoaffinity devices are designed for multiple uses. In this case, it is critical that the albumin captured on the affinity matrix is stripped from the column prior to regeneration of the matrix and processing of subsequent samples, to ensure no carryover and that maximal binding sites are available for subsequent samples. The current study examines the ability of a manufacturer's protocol to remove the proteins and peptides captured by an immunoaffinity spin column. The data presented in the current work illustrate the difficulty in completely removing albumin from the immunoaffinity device, and consequently, may explain the variability and decreased efficiency shown for this device in previous studies. In summary, the current data present important considerations for the implementation of multiple‐use immunoaffinity devices for processing subsequent clinical samples in a proteomic workflow.     

Efficient Hybrid Tandem Solar Cells Based on Optical Reinforcement of Colloidal Quantum Dots with Organic Bulk Heterojunctions

While colloidal quantum dot photovoltaic devices (CQDPVs) can achieve a power conversion efficiency (PCE) of ≈12%, their insufficient optical absorption in the near‐infrared (NIR) regime impairs efficient utilization of the full spectrum of visible light. Here, high‐efficiency, solution‐processed, hybrid series, tandem photovoltaic devices are developed featuring CQDs and organic bulk heterojunction (BHJ) photoactive materials for front‐ and back‐cells, respectively. The organic BHJ back‐cell efficiently harvests the transmitted NIR photons from the CQD front‐cell, which reinforces the photon‐to‐current conversion at 350–1000 nm wavelengths. Optimizing the short‐circuit current density balance of each sub‐cell and creating a near ideal series connection using an intermediate layer achieve a PCE (12.82%) that is superior to that of each single‐junction device (11.17% and 11.02% for the CQD and organic BHJ device, respectively). Notably, the PCE of the hybrid tandem device is the highest among the reported CQDPVs, including single‐junction devices and tandem devices. The hybrid tandem device also exhibits almost negligible degradation after air storage for 3 months. This study suggests a potential route to improve the performance of CQDPVs by proper hybridization with NIR‐absorbing photoactive materials.     

Integrating ZnO Microwires with Nanoscale Electrodes Using a Suspended PMMA Ribbon for Studying Reliable Electrical and Electromechanical Properties

A simple method for making electrical connections to ZnO microwires is reported. By using a suspended poly(methyl methacrylate) (PMMA) ribbon, it is shown that it is possible to electrically contact 1–2 μm diameter ZnO microwires with metal electrodes that are only 90 nm thick. The contact resistances of ZnO microwire‐based electronic devices fabricated by this method are lower than those of devices fabricated by standard electron‐beam lithography and evaporation processes. As one of the possible device applications from this fabrication method, suspended ZnO microwire‐based electromechanical devices are produced and their piezoelectric properties are investigated. Piezoelectric‐induced current is detected when the suspended microwires are induced to vibrate at their resonant frequency. This fabrication method can be readily and generally applied to prepare nanoscale electrodes on micrometer‐sized materials and provides a convenient means for studying their electrical and electromechanical phenomena in a reliable manner.     

Towards On-line Adaptation of Neuro-prostheses with Neuronal Evaluation Signals

Many experiments have successfully demonstrated that prosthetic devices for restoring lost body functions can in principle be controlled by brain signals. However, stable long-term application of these devices, required for paralyzed patients, may suffer substantially from on-going signal changes for example adapting neural activities or movements of the electrodes recording brain activity. These changes currently require tedious re-learning procedures which are conducted and supervised under laboratory conditions, hampering the everyday use of such devices. As an efficient alternative to current methods we here propose an on-line adaptation scheme that exploits a hypothetical secondary signal source from brain regions reflecting the user’s affective evaluation of the current neuro- prosthetic’s performance. For demonstrating the feasibility of our idea, we simulate a typical prosthetic setup controlling a virtual robotic arm. Hereby we use the additional, hypothetical evaluation signal to adapt the decoding of the intended arm movement which is subjected to large non-stationarities. Even with weak signals and high noise levels typically encountered in recording brain activities, our simulations show that prosthetic devices can be adapted successfully during everyday usage, requiring no special training procedures. Furthermore, the adaptation is shown to be stable against large changes in neural encoding and/or in the recording itself.