scholarly journals Development of an Electrostatic Comb-Driven MEMS Scanning Mirror for Two-Dimensional Raster Scanning

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 378
Author(s):  
Qiang Wang ◽  
Weimin Wang ◽  
Xuye Zhuang ◽  
Chongxi Zhou ◽  
Bin Fan

Microelectromechanical System (MEMS)-based scanning mirrors are important optical devices that have been employed in many fields as a low-cost and miniaturized solution. In recent years, the rapid development of Light Detection and Ranging (LiDAR) has led to opportunities and challenges for MEMS scanners. In this work, we propose a 2D electrostatically actuated micro raster scanner with relatively large aperture. The 2D scanner combines a resonant scanning axis driven by an in-plane comb and a quasistatic scanning axis driven by a vertical comb, which is achieved by raising the moving comb finger above the fixed comb finger through the residual stress gradient. The analytic formula for the resonant axis frequency, based on the mechanical coupling of two oscillation modes, is derived and compared with finite element simulation. A prototype is designed, fabricated, and tested, and an overall optical Field-of-View (FoV) of about 60° × 4° is achieved. Finally, some possibilities for further improvement or optimization are discussed.

2021 ◽  
Vol 11 (15) ◽  
pp. 6831
Author(s):  
Yue Chen ◽  
Jian Lu

With the rapid development of road traffic, real-time vehicle counting is very important in the construction of intelligent transportation systems (ITSs). Compared with traditional technologies, the video-based method for vehicle counting shows great importance and huge advantages in its low cost, high efficiency, and flexibility. However, many methods find difficulty in balancing the accuracy and complexity of the algorithm. For example, compared with traditional and simple methods, deep learning methods may achieve higher precision, but they also greatly increase the complexity of the algorithm. In addition to that, most of the methods only work under one mode of color, which is a waste of available information. Considering the above, a multi-loop vehicle-counting method under gray mode and RGB mode was proposed in this paper. Under gray and RGB modes, the moving vehicle can be detected more completely; with the help of multiple loops, vehicle counting could better deal with different influencing factors, such as driving behavior, traffic environment, shooting angle, etc. The experimental results show that the proposed method is able to count vehicles with more than 98.5% accuracy while dealing with different road scenes.


2020 ◽  
Vol 6 (3) ◽  
pp. 522-525
Author(s):  
Dorina Hasselbeck ◽  
Max B. Schäfer ◽  
Kent W. Stewart ◽  
Peter P. Pott

AbstractMicroscopy enables fast and effective diagnostics. However, in resource-limited regions microscopy is not accessible to everyone. Smartphone-based low-cost microscopes could be a powerful tool for diagnostic and educational purposes. In this paper, the imaging quality of a smartphone-based microscope with four different optical parameters is presented and a systematic overview of the resulting diagnostic applications is given. With the chosen configuration, aiming for a reasonable trade-off, an average resolution of 1.23 μm and a field of view of 1.12 mm2 was achieved. This enables a wide range of diagnostic applications such as the diagnosis of Malaria and other parasitic diseases.


2012 ◽  
Vol 459 ◽  
pp. 544-548 ◽  
Author(s):  
Wei Liang ◽  
Jian Bo Xu ◽  
Wei Hong Huang ◽  
Li Peng

Network security technology ensures secure data transmission in network. Meanwhile, it brings extra overhead of security system in terms of cost and performance, which seriously affects the rapid development of existing high-speed encryption systems. The existing encryption technology cannot meet the demand of high security, low cost and high real-time. For solving above problems, an ECC encryption engine architecture based on scalable public key cipher and a high-speed configurable multiplication algorithm are designed. The algorithm was tested on FPGA platform and the experiment results show that the system has better computation speed and lower cost overhead. By comparing with other systems, our system has benefits in terms of hardware overhead and encryption time ratio


2017 ◽  
Vol 31 (25) ◽  
pp. 1745001 ◽  
Author(s):  
Qiudong Guo ◽  
Peng Zhang ◽  
Lin Bo ◽  
Guibin Zeng ◽  
Dengqian Li ◽  
...  

With the rapid development of manufacturing technology of high temperature superconductive YB[Formula: see text]Cu3O[Formula: see text] YBCO materials and decreasing in cost of production, YBCO is marching into industrial areas with its good performances as source of high-magnetic field and rather low cost in reaching superconductivity. Based on analysis of the performance of high temperature superconductors YBCO and development of technology in superconductive magnetic separation both home and abroad, we propose a new approach of taking YBCO tape to make a solenoid as the source of a high magnetic field of magnetic separatior of ores. The paper also looks into the future of the YBCO high temperature superconductive magnetic separation from the perspective of technology and cost, as well as its applications in other industries.


2014 ◽  
Vol 540 ◽  
pp. 267-271
Author(s):  
Xin Liu ◽  
Lin Yan Li ◽  
Fan Yun Zeng ◽  
Xue Jun Wang ◽  
Sheng Ming Xu

With the rapid development and wide application of Li-ion batteries, cathode materials containing value metals Co, Ni and Mn are blended by several kind of metal oxide presently for pursuing high safe stability and low cost. The composition of spent Li-ion batteries has become complicated and optimum leaching condition varied. In this paper, leaching process for the mixture of pure LiCoO2and Li (Ni1/3Co1/3Mn1/3)O2was studied. With an increase in component of LiCoO2in mixed materials, the optimum leaching condition varied as: temperature from 60°C to 90°C, H2O2addition amount from 0.54 to 0.75ml/g and liquid-solid ratio from 10 to 20. According to this result, a real mixed spent batteries materials was recovered by being leached in 2M H2SO4at temperature of 90°C, liquid-solid ratio 20 and 0.6ml/g H2O2added. The leaching efficiencies of Co, Ni, Mn, Li were 96.88%, 93.71%, 92.12%, 99.43% respectively. Cu, Al and Fe in solution were removed by precipitation and solvent extraction. Finally, Ni, Co, Mn were extracted by D2EHPA for separating with Na+and other impurities, which is used as a raw materials for preparation of cathode active materials in batteries.


Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 257
Author(s):  
Sebastian Fudickar ◽  
Eike Jannik Nustede ◽  
Eike Dreyer ◽  
Julia Bornhorst

Caenorhabditis elegans (C. elegans) is an important model organism for studying molecular genetics, developmental biology, neuroscience, and cell biology. Advantages of the model organism include its rapid development and aging, easy cultivation, and genetic tractability. C. elegans has been proven to be a well-suited model to study toxicity with identified toxic compounds closely matching those observed in mammals. For phenotypic screening, especially the worm number and the locomotion are of central importance. Traditional methods such as human counting or analyzing high-resolution microscope images are time-consuming and rather low throughput. The article explores the feasibility of low-cost, low-resolution do-it-yourself microscopes for image acquisition and automated evaluation by deep learning methods to reduce cost and allow high-throughput screening strategies. An image acquisition system is proposed within these constraints and used to create a large data-set of whole Petri dishes containing C. elegans. By utilizing the object detection framework Mask R-CNN, the nematodes are located, classified, and their contours predicted. The system has a precision of 0.96 and a recall of 0.956, resulting in an F1-Score of 0.958. Considering only correctly located C. elegans with an [email protected] IoU, the system achieved an average precision of 0.902 and a corresponding F1 Score of 0.906.


2021 ◽  
Vol 21 (4) ◽  
pp. 1-23
Author(s):  
Bin Yuan ◽  
Chen Lin ◽  
Deqing Zou ◽  
Laurence Tianruo Yang ◽  
Hai Jin

The rapid development of the Internet of Things has led to demand for high-speed data transformation. Serving this purpose is the Tactile Internet, which facilitates data transfer in extra-low latency. In particular, a Tactile Internet based on software-defined networking (SDN) has been broadly deployed because of the proven benefits of SDN in flexible and programmable network management. However, the vulnerabilities of SDN also threaten the security of the Tactile Internet. Specifically, an SDN controller relies on the network status (provided by the underlying switches) to make network decisions, e.g., calculating a routing path to deliver data in the Tactile Internet. Hence, the attackers can compromise the switches to jeopardize the SDN and further attack Tactile Internet systems. For example, an attacker can compromise switches to launch distributed denial-of-service attacks to overwhelm the SDN controller, which will disrupt all the applications in the Tactile Internet. In pursuit of a more secure Tactile Internet, the problem of abnormal SDN switches in the Tactile Internet is analyzed in this article, including the cause of abnormal switches and their influences on different network layers. Then we propose an approach that leverages the messages sent by all switches to identify abnormal switches, which adopts a linear structure to store historical messages at a relatively low cost. By mapping each flow message to the flow establishment model, our method can effectively identify malicious SDN switches in the Tactile Internet and thus enhance its security.


2021 ◽  
Vol 21 (12) ◽  
pp. 6048-6053
Author(s):  
Qi Wang ◽  
Mingwei Li ◽  
Yao Xie ◽  
Yun Ou ◽  
Weiping Zhou

With the rapid development of the electronics industry, electronic products based on silicon and glass substrates electronic products will gradually be unable to meet the rising demand. Flexibility, environmental protection, and low costs are important for the development of electronic products. In this study, an efficient and low-cost method for preparing silver electrode structures by direct writing on paper has been demonstrated. Based on this method, a flexible paper-based sensor was prepared. The liquid printing ink used mainly comprises a precursor liquid without pre-prepared nanomaterials. The precursor liquid is transparent with good fluidity. Simple direct writing technology was used to write on the paper substrate using the precursor ink. When the direct-writing paper substrate was subsequently heated, silver nanostructures precipitated from the precursor liquid ink onto the paper substrate. The effect of different temperatures on the formation of the silver nanostructures and the influence of different direct writing processes on the structures were studied. Finally, a paper-based flexible sensor was prepared for finger-bending signal detection. The method is simple to operate and low in cost and can be used for the preparation of environment-friendly paper-based devices.


Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4312 ◽  
Author(s):  
Yunzhu Chen ◽  
Xingwei Xue

With the rapid development of the world’s transportation infrastructure, many long-span bridges were constructed in recent years, especially in China. However, these bridges are easily subjected to various damages due to dynamic loads (such as wind-, earthquake-, and vehicle-induced vibration) or environmental factors (such as corrosion). Therefore, structural health monitoring (SHM) is vital to guarantee the safety of bridges in their service lives. With its wide frequency response range, fast response, simple preparation process, ease of processing, low cost, and other advantages, the piezoelectric transducer is commonly employed for the SHM of bridges. This paper summarizes the application of piezoelectric materials for the SHM of bridges, including the monitoring of the concrete strength, bolt looseness, steel corrosion, and grouting density. For each problem, the application of piezoelectric materials in different research methods is described. The related data processing methods for four types of bridge detection are briefly summarized, and the principles of each method in practical application are listed. Finally, issues to be studied when using piezoelectric materials for monitoring are discussed, and future application prospects and development directions are presented.


Author(s):  
Hyun Choi ◽  
Wan-Chin Kim

Mechaless LiDAR technology, which does not have a mechanical drive part, has been actively studied in order to increase the reliability of the LiDAR device at low cost and drive environment in order to more actively apply LiDAR technology to autonomous driving. Mechaless LiDAR technology, which has been mainly studied recently, includes 3D Flash LiDAR technology, MEMS mirror utilization method, and OPA (Optical Phased Array). However, these methods have not been developed rapidly as a key technology for achieving autonomous driving due to low stability of driving environment or remarkably low measurable distance and FOV (field of view) compared with mechanical LiDAR. In this study, we investigated the improvement of FOV by using a flux-deflecting liquid lens and a fisheye lens that can achieve fine spatial resolution through continuous voltage regulation. Based on the initial design results, it was examined that the FOV can be secured to 80 ° or more by utilizing a relatively simple fisheye lens composed of only spherical lenses.


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