scholarly journals Thermophoretic Micron-Scale Devices: Practical Approach and Review

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 950 ◽  
Author(s):  
Namkyu Lee ◽  
Simone Wiegand
Keyword(s):  
Temperature Measurement ◽  
High Spatial Resolution ◽  
State Of The Art ◽  
Sample Volume ◽  
Medical Applications ◽  
Thermal Gradients ◽  
Technical Problems ◽  
Small Length Scale ◽  
On Chip ◽  
Microscopic Techniques

In recent years, there has been increasing interest in the development of micron-scale devices utilizing thermal gradients to manipulate molecules and colloids, and to measure their thermophoretic properties quantitatively. Various devices have been realized, such as on-chip implements, micro-thermogravitational columns and other micron-scale thermophoretic cells. The advantage of the miniaturized devices lies in the reduced sample volume. Often, a direct observation of particles using various microscopic techniques is possible. On the other hand, the small dimensions lead to some technical problems, such as a precise temperature measurement on small length scale with high spatial resolution. In this review, we will focus on the “state of the art” thermophoretic micron-scale devices, covering various aspects such as generating temperature gradients, temperature measurement, and the analysis of the current micron-scale devices. We want to give researchers an orientation for their development of thermophoretic micron-scale devices for biological, chemical, analytical, and medical applications.

scholarly journals Bioengineered Islet Cell Transplantation

2021 ◽  
Author(s):  
Kevin Bellofatto ◽  
Beat Moeckli ◽  
Charles-Henri Wassmer ◽  
Margaux Laurent ◽  
Graziano Oldani ◽  
...  
Keyword(s):  
State Of The Art ◽  
Diabetes Research ◽  
Islet Cell Transplantation ◽  
Β Cell ◽  
Cell Compartment ◽  
Factors Affecting ◽  
Insulin Activity ◽  
On Chip

Abstract Purpose of Review β cell replacement via whole pancreas or islet transplantation has greatly evolved for the cure of type 1 diabetes. Both these strategies are however still affected by several limitations. Pancreas bioengineering holds the potential to overcome these hurdles aiming to repair and regenerate β cell compartment. In this review, we detail the state-of-the-art and recent progress in the bioengineering field applied to diabetes research. Recent Findings The primary target of pancreatic bioengineering is to manufacture a construct supporting insulin activity in vivo. Scaffold-base technique, 3D bioprinting, macro-devices, insulin-secreting organoids, and pancreas-on-chip represent the most promising technologies for pancreatic bioengineering. Summary There are several factors affecting the clinical application of these technologies, and studies reported so far are encouraging but need to be optimized. Nevertheless pancreas bioengineering is evolving very quickly and its combination with stem cell research developments can only accelerate this trend.

scholarly journals Universal Stokes’s nanomechanical viscometer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Komal Chaudhary ◽  
Pooja Munjal ◽  
Kamal P. Singh
Keyword(s):  
Electric Field ◽  
Real Time ◽  
Sample Volume ◽  
Capillary Waves ◽  
Small Sample ◽  
Medical Applications ◽  
Rapid Measurement ◽  
Single Lens ◽  
Universal Applicability ◽  
Small Sample Volume

AbstractAlthough, many conventional approaches have been used to measure viscosity of fluids, most methods do not allow non-contact, rapid measurements on small sample volume and have universal applicability to all fluids. Here, we demonstrate a simple yet universal viscometer, as proposed by Stokes more than a century ago, exploiting damping of capillary waves generated electrically and probed optically with sub-nanoscale precision. Using a low electric field local actuation of fluids we generate quasi-monochromatic propagating capillary waves and employ a pair of single-lens based compact interferometers to measure attenuation of capillary waves in real-time. Our setup allows rapid measurement of viscosity of a wide variety of polar, non-polar, transparent, opaque, thin or thick fluids having viscosity values varying over four orders of magnitude from $$10^{0}{-}10^{4}~\text{mPa} \, \text{s}$$ 10 0 - 10 4 mPa s . Furthermore, we discuss two additional damping mechanisms for nanomechanical capillary waves caused by bottom friction and top nano-layer appearing in micro-litre droplets. Such self-stabilized droplets when coupled with precision interferometers form interesting microscopic platform for picomechanical optofluidics for fundamental, industrial and medical applications.

scholarly journals Analysis of the Practical Implementation of Flicker Measurement Coprocessor for AMI Meters

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1589
Author(s):  
Krzysztof Kołek ◽  
Andrzej Firlit ◽  
Krzysztof Piątek ◽  
Krzysztof Chmielowiec
Keyword(s):  
Code Generation ◽  
State Of The Art ◽  
Power Grids ◽  
Practical Implementation ◽  
System A ◽  
Measuring Devices ◽  
Point Representation ◽  
Measurement Algorithm ◽  
On Chip ◽  
Vhdl Code

Monitoring power quality (PQ) indicators is an important part of modern power grids’ maintenance. Among different PQ indicators, flicker severity coefficients Pst and Plt are measures of voltage fluctuations. In state-of-the-art PQ measuring devices, the flicker measurement channel is usually implemented as a dedicated processor subsystem. Implementation of the IEC 61000-4-15 compliant flicker measurement algorithm requires a significant amount of computational power. In typical PQ analysers, the flicker measurement is usually implemented as a part of the meter’s algorithm performed by the main processor. This paper considers the implementation of the flicker measurement as an FPGA module to offload the processor subsystem or operate as an IP core in FPGA-based system-on-chip units. The measurement algorithm is developed and validated as a Simulink diagram, which is then converted to a fixed-point representation. Parts of the diagram are applied for automatic VHDL code generation, and the classifier block is implemented as a local soft-processor system. A simple eight-bit processor operates within the flicker measurement coprocessor and performs statistical operations. Finally, an IP module is created that can be considered as a flicker coprocessor module. When using the coprocessor, the main processor’s only role is to trigger the coprocessor and read the results, while the coprocessor independently calculates the flicker coefficients.

scholarly journals Thermographic Study of Chip Temperature in High-Speed Dry Milling Magnesium Alloys

2016 ◽  
Vol 7 (2) ◽  
pp. 86-92 ◽  
Author(s):  
Józef Kuczmaszewski ◽  
Ireneusz Zagórski ◽  
Piotr Zgórniak
Keyword(s):  
Temperature Measurement ◽  
Magnesium Alloys ◽  
High Speed ◽  
Machining Process ◽  
Dry Milling ◽  
Technological Parameters ◽  
Chip Temperature ◽  
Thermographic Study ◽  
On Chip ◽  
The Impact

Abstract This paper presents an overview of the state of knowledge on temperature measurement in the cutting area during magnesium alloy milling. Additionally, results of own research on chip temperature measurement during dry milling of magnesium alloys are included. Tested magnesium alloys are frequently used for manufacturing elements applied in the aerospace industry. The impact of technological parameters on the maximum chip temperature during milling is also analysed. This study is relevant due to the risk of chip ignition during the machining process.

scholarly journals Argus CNN Accelerator Based on Kernel Clustering and Resource-Aware Pruning

2021 ◽  
Vol 27 (3) ◽  
pp. 57-70
Author(s):  
Damjan M. Rakanovic ◽  
Vuk Vranjkovic ◽  
Rastislav J. R. Struharik
Keyword(s):  
Digital Signal Processor ◽  
State Of The Art ◽  
Digital Signal ◽  
Pruning Algorithm ◽  
Kernel Clustering ◽  
Field Programmable ◽  
Comparable Performance ◽  
On Chip ◽  
Resource Characteristics ◽  
Resource Aware

Paper proposes a two-step Convolutional Neural Network (CNN) pruning algorithm and resource-efficient Field-programmable gate array (FPGA) CNN accelerator named “Argus”. The proposed CNN pruning algorithm first combines similar kernels into clusters, which are then pruned using the same regular pruning pattern. The pruning algorithm is carefully tailored for FPGAs, considering their resource characteristics. Regular sparsity results in high Multiply-accumulate (MAC) efficiency, reducing the amount of logic required to balance workloads among different MAC units. As a result, the Argus accelerator requires about 170 Look-up tables (LUTs) per Digital Signal Processor (DSP) block. This number is close to the average LUT/DPS ratio for various FPGA families, enabling balanced resource utilization when implementing Argus. Benchmarks conducted using Xilinx Zynq Ultrascale + Multi-Processor System-on-Chip (MPSoC) indicate that Argus is achieving up to 25 times higher frames per second than NullHop, 2 and 2.5 times higher than NEURAghe and Snowflake, respectively, and 2 times higher than NVDLA. Argus shows comparable performance to MIT’s Eyeriss v2 and Caffeine, requiring up to 3 times less memory bandwidth and utilizing 4 times fewer DSP blocks, respectively. Besides the absolute performance, Argus has at least 1.3 and 2 times better GOP/s/DSP and GOP/s/Block-RAM (BRAM) ratios, while being competitive in terms of GOP/s/LUT, compared to some of the state-of-the-art solutions.

scholarly journals Handheld Microflow Cytometer Based on a Motorized Smart Pipette, a Microfluidic Cell Concentrator, and a Miniaturized Fluorescence Microscope

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2761 ◽  
Author(s):  
Byeongyeon Kim ◽  
Dayoung Kang ◽  
Sungyoung Choi
Keyword(s):  
Flow Cytometry ◽  
High Throughput ◽  
Flow Cytometric Analysis ◽  
Sample Volume ◽  
Fluorescence Microscope ◽  
Comprehensive Approach ◽  
Optical Systems ◽  
Simple Protocol ◽  
Microflow Cytometer ◽  
On Chip

Miniaturizing flow cytometry requires a comprehensive approach to redesigning the conventional fluidic and optical systems to have a small footprint and simple usage and to enable rapid cell analysis. Microfluidic methods have addressed some challenges in limiting the realization of microflow cytometry, but most microfluidics-based flow cytometry techniques still rely on bulky equipment (e.g., high-precision syringe pumps and bench-top microscopes). Here, we describe a comprehensive approach that achieves high-throughput white blood cell (WBC) counting in a portable and handheld manner, thereby allowing the complete miniaturization of flow cytometry. Our approach integrates three major components: a motorized smart pipette for accurate volume metering and controllable liquid pumping, a microfluidic cell concentrator for target cell enrichment, and a miniaturized fluorescence microscope for portable flow cytometric analysis. We first validated the capability of each component by precisely metering various fluid samples and controlling flow rates in a range from 219.5 to 840.5 μL/min, achieving high sample-volume reduction via on-chip WBC enrichment, and successfully counting single WBCs flowing through a region of interrogation. We synergistically combined the three major components to create a handheld, integrated microflow cytometer and operated it with a simple protocol of drawing up a blood sample via pipetting and injecting the sample into the microfluidic concentrator by powering the motorized smart pipette. We then demonstrated the utility of the microflow cytometer as a quality control means for leukoreduced blood products, quantitatively analyzing residual WBCs (rWBCs) in blood samples present at concentrations as low as 0.1 rWBCs/μL. These portable, controllable, high-throughput, and quantitative microflow cytometric technologies provide promising ways of miniaturizing flow cytometry.

Decoupling spatial and temporal processes for clinical analyzers

1995 ◽  
Vol 41 (9) ◽  
pp. 1398-1402
Author(s):  
J Mazza ◽  
M Huber ◽  
S Frye
Keyword(s):  
Number Theory ◽  
Design Problem ◽  
State Of The Art ◽  
Spatial Arrangement ◽  
Sample Volume ◽  
Complex Task ◽  
Clinical Testing ◽  
Time And Space ◽  
Physical Processing ◽  
Temporal And Spatial

Abstract The separation of time and space in processing a sample greatly simplifies the design of automation for clinical testing. The efficient spatial arrangement of analytical units and sample manipulators has become a more complex task because of the degree of automation required on today's state-of-the-art analyzer. Minimization of sample volume and the reduction of overall analyzer size further complicate the design problem. We report the development of a proprietary method of decoupling the temporal and spatial elements required for analysis of samples. This process is based on number theory and can be used to optimize the distance between the physical processing stations while allowing these same stations to operate on samples over a substantial range of times. The technique is versatile and can also be used when it is desirable to sequentially move groups of items from location to location.

scholarly journals Progress in Cooling Nanoelectronic Devices to Ultra-Low Temperatures

2020 ◽  
Vol 201 (5-6) ◽  
pp. 772-802 ◽  
Author(s):  
A. T. Jones ◽  
C. P. Scheller ◽  
J. R. Prance ◽  
Y. B. Kalyoncu ◽  
D. M. Zumbühl ◽  
...  
Keyword(s):  
State Of The Art ◽  
Electronic Devices ◽  
Bulk Materials ◽  
Nanoelectronic Devices ◽  
Current State ◽  
Physical Effects ◽  
On Chip ◽  
Nanoscale Physics ◽  
A Current ◽  
Made In

AbstractHere we review recent progress in cooling micro-/nanoelectronic devices significantly below 10 mK. A number of groups worldwide are working to produce sub-millikelvin on-chip electron temperatures, motivated by the possibility of observing new physical effects and improving the performance of quantum technologies, sensors and metrological standards. The challenge is a longstanding one, with the lowest reported on-chip electron temperature having remained around 4 mK for more than 15 years. This is despite the fact that microkelvin temperatures have been accessible in bulk materials since the mid-twentieth century. In this review, we describe progress made in the last 5 years using new cooling techniques. Developments have been driven by improvements in the understanding of nanoscale physics, material properties and heat flow in electronic devices at ultralow temperatures and have involved collaboration between universities and institutes, physicists and engineers. We hope that this review will serve as a summary of the current state of the art and provide a roadmap for future developments. We focus on techniques that have shown, in experiment, the potential to reach sub-millikelvin electron temperatures. In particular, we focus on on-chip demagnetisation refrigeration. Multiple groups have used this technique to reach temperatures around 1 mK, with a current lowest temperature below 0.5 mK.

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