scholarly journals A Peristaltic Micropump Based on the Fast Electrochemical Actuator: Design, Fabrication, and Preliminary Testing

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 62
Author(s):  
Ilia Uvarov ◽  
Pavel Shlepakov ◽  
Artem Melenev ◽  
Kechun Ma ◽  
Vitaly Svetovoy ◽  
...  

Microfluidic devices providing an accurate delivery of fluids at required rates are of considerable interest, especially for the biomedical field. The progress is limited by the lack of micropumps, which are compact, have high performance, and are compatible with standard microfabrication. This paper describes a micropump based on a new driving principle. The pump contains three membrane actuators operating peristaltically. The actuators are driven by nanobubbles of hydrogen and oxygen, which are generated in the chamber by a series of short voltage pulses of alternating polarity applied to the electrodes. This process guaranties the response time of the actuators to be much shorter than that of any other electrochemical device. The main part of the pump has a size of about 3 mm, which is an order of magnitude smaller in comparison with conventional micropumps. The pump is fabricated in glass and silicon wafers using standard cleanroom processes. The channels are formed in SU-8 photoresist and the membrane is made of SiNx. The channels are sealed by two processes of bonding between SU-8 and SiNx. Functionality of the channels and membranes is demonstrated. A defect of electrodes related to the lift-off fabrication procedure did not allow a demonstration of the pumping process although a flow rate of 1.5 µl/min and dosage accuracy of 0.25 nl are expected. The working characteristics of the pump make it attractive for the use in portable drug delivery systems, but the fabrication technology must be improved.

2021 ◽  
Vol 7 (3) ◽  
pp. eabd6978 ◽  
Author(s):  
Jingxin Zhao ◽  
Hongyu Lu ◽  
Yan Zhang ◽  
Shixiong Yu ◽  
Oleksandr I. Malyi ◽  
...  

Coaxial fiber-shaped supercapacitors with short charge carrier diffusion paths are highly desirable as high-performance energy storage devices for wearable electronics. However, the traditional approaches based on the multistep fabrication processes for constructing the fiber-shaped energy device still encounter persistent restrictions in fabrication procedure, scalability, and mechanical durability. To overcome this critical challenge, an all-in-one coaxial fiber-shaped asymmetric supercapacitor (FASC) device is realized by a direct coherent multi-ink writing three-dimensional printing technology via designing the internal structure of the coaxial needles and regulating the rheological property and the feed rates of the multi-ink. Benefitting from the compact coaxial structure, the FASC device delivers a superior areal energy/power density at a high mass loading, and outstanding mechanical stability. As a conceptual exhibition for system integration, the FASC device is integrated with mechanical units and pressure sensor to realize high-performance self-powered mechanical devices and monitoring systems, respectively.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amir Muhammad Afzal ◽  
In-Gon Bae ◽  
Yushika Aggarwal ◽  
Jaewoo Park ◽  
Hye-Ryeon Jeong ◽  
...  

AbstractHybrid organic–inorganic perovskite materials provide noteworthy compact systems that could offer ground-breaking architectures for dynamic operations and advanced engineering in high-performance energy-harvesting optoelectronic devices. Here, we demonstrate a highly effective self-powered perovskite-based photodiode with an electron-blocking hole-transport layer (NiOx). A high value of responsivity (R = 360 mA W−1) with good detectivity (D = 2.1 × 1011 Jones) and external quantum efficiency (EQE = 76.5%) is achieved due to the excellent interface quality and suppression of the dark current at zero bias voltage owing to the NiOx layer, providing outcomes one order of magnitude higher than values currently in the literature. Meanwhile, the value of R is progressively increased to 428 mA W−1 with D = 3.6 × 1011 Jones and EQE = 77% at a bias voltage of − 1.0 V. With a diode model, we also attained a high value of the built-in potential with the NiOx layer, which is a direct signature of the improvement of the charge-selecting characteristics of the NiOx layer. We also observed fast rise and decay times of approximately 0.9 and 1.8 ms, respectively, at zero bias voltage. Hence, these astonishing results based on the perovskite active layer together with the charge-selective NiOx layer provide a platform on which to realise high-performance self-powered photodiode as well as energy-harvesting devices in the field of optoelectronics.


1999 ◽  
Author(s):  
R. Ye ◽  
J. H. Ding ◽  
H. S. Tzou

Abstract Recent development of smart structures and structronic systems has demonstrated the technology in many engineering applications. Active structural control of aircraft wings or helicopter blades (e.g., shapes, flaps, leading and/or trailing edges) can significantly enhance the aerodynamic efficiency and flight maneuverability of high-performance airplanes and helicopters. This paper in to evaluate the dual bending and torsion vibration control effects of an X-actuator configuration reconfigured from a parallel configuration. Finite element (FE) formation of a new FE using the layerwise constant shear angle theory is reviewed and the derived governing equations are discussed. Bending and torsion control effects of plates are studied using the FE method and also demonstrated via laboratory experiments. FE and experimental results both suggest the X-actuator is effective to both bending and torsion control of plates.


2020 ◽  
Author(s):  
Marcus H. Hansen ◽  
Anita T. Simonsen ◽  
Hans B. Ommen ◽  
Charlotte G. Nyvold

AbstractBackgroundRapid and practical DNA-sequencing processing has become essential for modern biomedical laboratories, especially in the field of cancer, pathology and genetics. While sequencing turn-over time has been, and still is, a bottleneck in research and diagnostics, the field of bioinformatics is moving at a rapid pace – both in terms of hardware and software development. Here, we benchmarked the local performance of three of the most important Spark-enabled Genome analysis toolkit 4 (GATK4) tools in a targeted sequencing workflow: Duplicate marking, base quality score recalibration (BQSR) and variant calling on targeted DNA sequencing using a modest hyperthreading 12-core single CPU and a high-speed PCI express solid-state drive.ResultsCompared to the previous GATK version the performance of Spark-enabled BQSR and HaplotypeCaller is shifted towards a more efficient usage of the available cores on CPU and outperforms the earlier GATK3.8 version with an order of magnitude reduction in processing time to analysis ready variants, whereas MarkDuplicateSpark was found to be thrice as fast. Furthermore, HaploTypeCallerSpark and BQSRPipelineSpark were significantly faster than the equivalent GATK4 standard tools with a combined ∼86% reduction in execution time, reaching a median rate of ten million processed bases per second, and duplicate marking was reduced ∼42%. The called variants were found to be in close agreement between the Spark and non-Spark versions, with an overall concordance of 98%. In this setup, the tools were also highly efficient when compared execution on a small 72 virtual CPU/18-node Google Cloud cluster.ConclusionIn conclusion, GATK4 offers practical parallelization possibilities for DNA sequence processing, and the Spark-enabled tools optimize performance and utilization of local CPUs. Spark utilizing GATK variant calling is several times faster than previous GATK3.8 multithreading with the same multi-core, single CPU, configuration. The improved opportunities for parallel computations not only hold implications for high-performance cluster, but also for modest laboratory or research workstations for targeted sequencing analysis, such as exome, panel or amplicon sequencing.


2014 ◽  
pp. 979-991
Author(s):  
Georgia Tsiliki ◽  
Manolis Tzagarakis ◽  
Spyros Christodoulou ◽  
Sophia Kossida ◽  
Nikos Karacapilidis

Web 2.0 technologies applications have been suggested as potential enablers for the accumulation of multidisciplinary knowledge, for instance in the biomedical field. Such applications offer new ways of creating, collaborating and sharing user-generated content online. Under this context, the authors' present an innovative Web 2.0 approach that exploits prominent high-performance computing paradigms and large data processing technologies to meaningfully search, analyze and aggregate data existing in diverse, extremely large and rapidly evolving sources. The underlying tool is designed to support the entire life cycle of a biomedical collaboration, with specifically implemented services. Preliminary evaluation results are also presented and discussed.


1984 ◽  
Vol 247 (4) ◽  
pp. R733-R739 ◽  
Author(s):  
J. P. Davis ◽  
G. C. Stephens

Larvae of Dendraster excentricus were produced by collecting gametes and carrying out fertilization under aseptic conditions. Since gametes are free of bacteria in the gonad, bacteria-free (axenic) suspensions of larvae result. Net rates of entry of 14 amino acids and the rate of production of ammonia were simultaneously determined by high-performance liquid chromatography. The net rates of uptake of neutral amino acids were an order of magnitude greater than rates for basic and acidic amino acids. Influx of 14C-labeled leucine, arginine, and glutamate accurately reflects the net entry rate of these substrates. Uptake of amino acids by axenic suspensions of larvae was compared with uptake by suspensions prepared without aseptic precautions. There was no significant difference in net uptake of the 14 amino acids or in the pattern of oxidation and assimilation of [14C]leucine during short-term experiments of 4-h duration or less.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Li Qin Zhou ◽  
Chen Ling ◽  
Hui Zhou ◽  
Xiang Wang ◽  
Joseph Liao ◽  
...  

Abstract The efficiency of sunlight-driven reduction of carbon dioxide (CO2), a process mimicking the photosynthesis in nature that integrates the light harvester and electrolysis cell to convert CO2 into valuable chemicals, is greatly limited by the sluggish kinetics of oxygen evolution in pH-neutral conditions. Current non-noble metal oxide catalysts developed to drive oxygen evolution in alkaline solution have poor performance in neutral solutions. Here we report a highly active and stable oxygen evolution catalyst in neutral pH, Brownmillerite Sr2GaCoO5, with the specific activity about one order of magnitude higher than that of widely used iridium oxide catalyst. Using Sr2GaCoO5 to catalyze oxygen evolution, the integrated CO2 reduction achieves the average solar-to-CO efficiency of 13.9% with no appreciable performance degradation in 19 h of operation. Our results not only set a record for the efficiency in sunlight-driven CO2 reduction, but open new opportunities towards the realization of practical CO2 reduction systems.


Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1285 ◽  
Author(s):  
Haleh Nazemi ◽  
Aashish Joseph ◽  
Jaewoo Park ◽  
Arezoo Emadi

Micro- and nano-sensors lie at the heart of critical innovation in fields ranging from medical to environmental sciences. In recent years, there has been a significant improvement in sensor design along with the advances in micro- and nano-fabrication technology and the use of newly designed materials, leading to the development of high-performance gas sensors. Advanced micro- and nano-fabrication technology enables miniaturization of these sensors into micro-sized gas sensor arrays while maintaining the sensing performance. These capabilities facilitate the development of miniaturized integrated gas sensor arrays that enhance both sensor sensitivity and selectivity towards various analytes. In the past, several micro- and nano-gas sensors have been proposed and investigated where each type of sensor exhibits various advantages and limitations in sensing resolution, operating power, response, and recovery time. This paper presents an overview of the recent progress made in a wide range of gas-sensing technology. The sensing functionalizing materials, the advanced micro-machining fabrication methods, as well as their constraints on the sensor design, are discussed. The sensors’ working mechanisms and their structures and configurations are reviewed. Finally, the future development outlook and the potential applications made feasible by each category of the sensors are discussed.


2019 ◽  
Vol 9 (1) ◽  
pp. 130 ◽  
Author(s):  
Kyungwoo Lee ◽  
Yonghyun Choi ◽  
Kyobum Kim ◽  
Hyung-Jun Koo ◽  
Jonghoon Choi

In order to quantify the amount of drug molecules in drug delivery systems, analytical techniques such as high-performance liquid chromatography are used due to their accuracy and reliability. However, the instruments required for such techniques are expensive and not available in all laboratories. Therefore, in this study, we introduce a method that can be a relatively inexpensive and easy to perform drug analysis in almost any laboratory set-up. We have devised the “average-weight-difference method” within the limits of existing spectral analyses. By employing this method, we quantitatively analyzed the amount of isoniazid or doxorubicin molecules loaded onto β-glucan nanoparticles. This proved to be a relatively simple and reliable method and can be used to estimate the amount of nanoscale biomolecules before their analysis through expensive equipment in an environment where the instruments are not readily available.


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