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An Effective Recognition Method for Particle Coincidence in Double Differential Impedance Cytometry

IEEE SENSORS JOURNAL 2023年第16期23卷 18070-18080页

作者： Li, Shanshan Wang, Chao Yang, Bowen Liang, Xinyi Li, Junwei Hebei Univ Technol Sch Mech Engn Hebei Key Lab Smart Sensing & Human Robot Interact State Key Lab Reliabil & Intelligence Elect Equipm Tianjin 300130 Peoples R China Hebei Univ Technol Sch Mech Engn Hebei Key Lab Smart Sensing & Human Robot Interact Tianjin 300130 Peoples R China Hebei Univ Technol Inst Biophys Sch Hlth Sci & Biomed Engn Tianjin 300401 Peoples R China

As a label-free single cell analysis approach, impedance flow cytometry provides valuable information by differential signals. However, for high throughput purpose, particle coincidence is inevitable especially when the cell concentration or pumping rate is too high. In this work, we proposed the first numerical model and a novel method for particle coincidence. To investigate the multiparticle events, a double differential impedance sensor is used. From a statistic analysis of signal peaks, we could determine the threshold of particle events and then read out particle numbers. Compared with customized threshold, the data-driven cutoff line fundamentally improves the accuracy of particle recognition. Herein, the key operation parameters that influence the particle coincidence including sample concentration, driven pressure (stands for pumping rate), and sensor configuration are elucidated. Moreover, a guide to the best practices to avoid multiparticle coincidence events is suggested for real applications.

关键词： Double differential impedance flow cytometry multiparticle particle coincidence

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Easy-to-Operate Co-flow Step Emulsification Device for Droplet Digital Polymerase Chain Reaction

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ANALYTICAL CHEMISTRY 2022年第9期94卷 3939-3947页

作者： Wei, Chunyang Yu, Chengzhuang Li, Shanshan Meng, Jiyu Li, Tiejun Cheng, Jingmeng Pan, Feng Li, Junwei Hebei Univ Technol Hebei Key Lab Robot Sensing & Human Robot Interac Sch Mech Engn Tianjin 300132 Peoples R China Hebei Univ Technol State Key Lab Reliabil & Intelligence Elect Equip Tianjin 300130 Peoples R China Hebei Univ Technol Inst Biophys Sch Hlth Sci & Biomed Engn Tianjin 300401 Peoples R China Hebei Univ Technol Dept Elect & Informat Engn Langfang 065000 Peoples R China

Digital polymerase chain reaction (PCR) plays important roles in the detection and quantification of nucleic acid targets, while there still remain challenges including high cost, complex operation, and low integration of the instrumental system. Here, in this work, a novel microfluidic chip based on co-flow step emulsification is proposed for droplet digital PCR (ddPCR), which can achieve droplet generation, droplet array self-assembly, PCR amplification, and fluorescence detection on a single device. With the combination of single-layer lithography and punching operation, a step microstructure was constructed and it served as the key element to develop a Laplace pressure gradient at the Rayleigh-Plateau instability interface so as to achieve droplet generation. It is demonstrated that the fabrication of step microstructure is low cost, easy-to-operate, and reliable. In addition, the single droplet volume can be adjusted flexibly due to the co-flow design;thus, the ddPCR chip can get an ultrahigh upper limit of quantification to deal with DNA templates with high concentrations. Furthermore, the volume fraction of the resulting droplets in this ddPCR chip can be up to 72% and it results in closely spaced droplet arrays, makes the best of CCD camera for fluorescence detections, and is beneficial for the minimization of a ddPCR system. The quantitative capability of the ddPCR chip was evaluated by measuring template DNA at concentrations from 20 to 50 000 copies/mu L. Owing to the characteristics of low cost, easy operation, excellent quantitative capability, and minimization, the proposed ddPCR chip meets the requirements of DNA molecule quantification and is expected to be applied in the point-of-care testing field.

关键词： lab-on-a-chip Microfluidics

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Effects of sintering in a high magnetic field on properties of vitrified bond and vitrified CBN composites

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CERAMICS INTERNATIONAL 2018年第18期44卷 22301-22307页

作者： Wang, Xuezhi Sun, Xue Ma, Zhelun Yu, Tianbiao Wang, Wanshan Hebei Univ Technol Sch Mech Engn Tianjin 300401 Peoples R China Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300401 Peoples R China Northeastern Univ Sch Mech Engn & Automat Shenyang 110819 Liaoning Peoples R China

Vitrified bond CBN grinding wheels are being widely used due to their superior performance. Also, advantages of vitrified grinding wheels are high elastic modulus, stable chemical property, and low thermal expansion coefficient. Brittleness and low strength are key factors restricting the development of vitrified bond CBN grinding wheels. In this paper, the sintering in a high magnetic field was innovatively introduced into the manufacturing of vitrified bond CBN grinding wheels, and the effects of sintering in a high magnetic field on properties on vitrified bond and vitrified CBN composites were systematically investigated. Vitrified bond was characterized using three-point bending, scanning electron microscopy, X-ray diffraction. It was observed that microstructure of vitrified bond could be changed, grain orientation could be controlled and average grain size could be decreased in a high magnetic field, while vitrified bond strength could be simultaneously improved. High quality vitrified bond could be obtained by appropriately adjusting the strength and direction of high magnetic field. Results demonstrated that vitrified bond properties were improved when the magnetic field strength was 6 T. In order to highlight the high magnetic field effect on the vitrified CBN composites, the ordinary CBN abrasives and nickel plated CBN abrasives were used respectively. Microstructures, bending strengths of vitrified CBN composites were compared in different high magnetic fields. When the magnetic field strength was appropriate (less than 6 T), the binding characteristic of vitrified bond CBN composites with nickel plated CBN abrasives was greatly improved. The highest bending strength value of vitrified CBN composites was 79.5 MPa in 6 T high magnetic field.

关键词： High magnetic field Vitrified bond Vitrified CBN composites Grain orientation

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Organization and Understanding of a Tactile Information Dataset TacAct For Physical human-robot interaction

Organization and Understanding of a Tactile Information Data...

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IEEE/RSJ International Conference on Intelligent robots and Systems (IROS)

作者： Wang, Peng Liu, Jixiao Hou, Funing Chen, Dicai Xia, Zihou Guo, Shijie Hebei Univ Technol Sch Mech Engn Tianjin Peoples R China Hebei Univ Technol Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300132 Peoples R China

ISBN: (纸本)9781665417143

human touching the robot to convey intentions or emotions is an essential communication pathway during physical human-robot interaction (pHRI). Therefore, advanced service robots require superior tactile intelligence to guarantee naturalness and safety when making physical contact with human subjects. Tactile intelligence is the capability to percept and recognize tactile information from touch behaviors, in which understanding the physical meaning of touching actions is crucial. For this purpose, this report introduces a recently collected and organized dataset "TacAct" that encloses real-time tactile information when human subjects touched the test device mimicking a robot forearm. The dataset contains 12 types of 24,000 touch actions from 50 subjects. The dataset details are described, the data are preliminarily analyzed, and the validity of the dataset is tested through a convolutional neural network LeNet-5 which classifying different types of touch actions. We believe that the TacAct dataset would be beneficial for the community to understand the touch intention under various circumstances and to develop learning-based intelligent algorithms for different applications.

关键词： Service robots robot control human-robot interaction Organizations Real-time systems Safety Classification algorithms

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Observer-based finite-time control for trajectory tracking of lower extremity exoskeleton

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING 2022年第2期236卷 257-269页

作者： Wang, Jie Liu, Jiahao Chen, Lingling Guo, Shijie Univ Sci & Technol Beijing Inst Artificial Intelligence Beijing Peoples R China Hebei Univ Technol Sch Artificial Intelligence & Data Sci Guangrong Rd Tianjin 300130 Peoples R China Engn Res Ctr Intelligent Rehabil Minist Educ Tianjin Peoples R China Hebei Key Lab Robot Sensing & Human Robot Interac Tianjin Peoples R China

In this article, an advanced observer-based finite-time trajectory tracking controller is investigated for lower extremity exoskeleton without available joint angular velocities to improve the movement ability of dependent persons, which is robust against uncertain dynamics, human active joint torque and external disturbances. First, the Lagrange principle is applied to analyze the dynamic properties of lower extremity exoskeleton driven by artificial pneumatic muscles, and its swing phase model is established. After that, a novel finite-time extended state observer is proposed to observe the lumped disturbances and unavailable angular velocities of the lower limb exoskeleton simultaneously. Furthermore, a finite-time sliding mode controller of exoskeleton is designed based on the extended state observer, and the finite-time convergence of tracking error is rigorously demonstrated based on the Lyapunov theory. Finally, the control system simulation is established and experimental tests are conducted with a voluntary subject during flexion of wearer's knee and hip joints, the obtained results demonstrate fast and high-precision tracking performance of the proposed approach.

关键词： Lower extremity exoskeleton sliding mode control finite-time control Lyapunov theory extended state observer

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Cost-Efficient Flexible Supercapacitive Tactile Sensor With Superior Sensitivity and High Spatial Resolution for human-robot interaction

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IEEE ACCESS 2020年 8卷 64836-64845页

作者： Liu, Jixiao Wang, Manfei Wang, Peng Hou, Funing Meng, Chuizhou Hashimoto, Kazunobu Guo, Shijie Hebei Univ Technol State Key Lab Reliabil & Intelligence Elect Equip Tianjin 300401 Peoples R China Hebei Univ Technol Hebei Key Lab Robot Percept & Human Robot Interac Tianjin 300401 Peoples R China Hebei Univ Technol Sch Mech Engn Tianjin 300401 Peoples R China Fudan Univ Acad Engn & Technol Shanghai 200433 Peoples R China

Tactile sensing is crucial for the safety, accuracy and robustness of the human-robot interactions in the fields of wearable equipment, service robots and healthcare robots. Although many efforts have been made, it still requires much work to develop functional and reliable flexible tactile sensors with superior sensitivity, wide measurement range, high spatial resolution and low cost based on simple structures and easy fabrication. Here, this paper introduces a flexible supercapacitive tactile sensor with outstanding and balanced performance. The tactile sensor contains two layers of flexible electrodes and a layer of ionic-gel coated microfiber matrix to form a supercapacitive sensing structure. The flexible electrodes and the ionic microfiber matrix are processed with scalable techniques such as screen printing and gel-coating, which guarantee the ultra-flexibility and low fabrication cost. The experimental data suggests strong linearity in the pressure-capacitance relationship and high sensitivity (135.9 ***(-1).cm(2) or 27.11 kPa(-1)) pressure measurement range (from 0 kPa to 1200 kPa) is also achieved by balancing structure parameters. Dynamic responses of the tactile sensors could accurately reflect the applied pressure cycles from human-finger tapping and machine pressing. The tactile sensor can map the pressure distribution with a high spatial resolution (>2 ***(-2)) when connected with the specially designed electric circuitry. The spatial resolution from sub-mm to large area makes it promising for various sensing applications in human-robot interactions, from finger touch to body contact. The developed tactile sensor in this study owns superior applicability and universality which makes it a trustworthy candidate to benefit various applications in robotics, flexible electronics and bioengineered equipment.

关键词： human-robot interaction supercapacitive tactile sensor

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A low cost and portable smartphone microscopic device for cell counting

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SENSORS AND ACTUATORS A-PHYSICAL 2018年 274卷 57-63页

作者： Zeng, Yujin Jin, Ke Li, Jie Liu, Jixiao Li, Junwei Li, Tiejun Li, Shanshan Hebei Univ Technol Sch Mech Engn Tianjin 300130 Peoples R China Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300401 Peoples R China Hebei Univ Technol Sch Architecture & Design Tianjin 300401 Peoples R China Hebei Univ Technol Inst Biophys Tianjin 300401 Peoples R China

Portable smartphone microscopic devices can potentially address various imaging and cell counting needs in healthcare monitoring. In this paper, a portable microscopic platform is constructed by a commercial smartphone and a custom-designed slider-scale microfluidic chip. Here the smartphone acts both as a detector and image analysis station. We demonstrate the adaptation of a smartphone's camera by loading a single-ball lens to function as a compact microscope, and then a glass slider or a slider-scale multiplex microfluidic chip is designed for preprocess of the samples. Our portable imaging device allows for micron size resolution and a home-coded Android application is performed for automatic/manual particle counting. Pumpkin pollen powders on a slider were counted as a demo test and then the counting for dairy somatic cells within a microfluidic chip were carried out automatically. The results from the smartphone microscopic device show good agreement with those values done by commercial microscope and flowcytometry. With advances in miniaturized electronics and smartphones, this low cost and portable smartphone microscopic platform can be used as common and convenient tools to perform true point-of-care biomedical or biochemical lab-on-a-chip applications. (C) 2018 Elsevier B.V. All rights reserved.

关键词： Microscopic Smartp hone Portable Cell counting Low cost

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Dynamic positioning accuracy of dual-axis drive mechanism of satellite antenna with multi-clearance coupling

Dynamic positioning accuracy of dual-axis drive mechanism of...

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Asia Conference on Mechanical Engineering and Aerospace Engineering (MEAE)

作者： Qi, Chaoqun Zhang, Huibo You, Bindi Fan, Jizhuang Dai, Shijie Hebei Univ Technol Hebei Key Lab Robot Sensing & Human Robot Interac Tianjin 300130 Peoples R China Harbin Inst Technol Weihai Sch Naval Architecture & Ocean Engn Weihai 264209 Shandong Peoples R China Harbin Inst Technol State Key Lab Robot & Syst Harbin 150001 Heilongjiang Peoples R China

The dual-axis drive mechanism of satellite antenna as a typical multi joint aerospace mechanism consists of azimuth axis and pitch axis. The multi-clearance contained within those drive joint cause contact and impact in joint, and consequently affect the dynamic positioning accuracy. A nonlinear dynamic model of planetary gears with multiple clearances couplings is proposed to investigate the influence mechanism of clearances on the dynamic performances. The nonlinear factors such as radial clearance, backlash and time-varying meshing stiffness of the bearing are considered in the model. And the dynamic model of double-axis driving mechanism of satellite antenna with multi-clearance coupling is established. Then positional and rotational speed error curves of antenna reflector at different rotational speed are respectively analyzed. The numerical simulation results show that the influence of multi-clearance coupling on the dynamic positioning accuracy of double-axis drive mechanism of satellite antenna is remarkable.

关键词： Satellite antennas

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Game scene construction for lower limb rehabilitation robot based on virtual reality 5

Game scene construction for lower limb rehabilitation robot ...

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5th International Conference on Electromechanical Control Technology and Transportation (ICECTT)

作者： Feng, Yongfei Jin, Di Shao, Qianjun Vladareanu, Luige Niu, Jianye Wang, Hongbo Ningbo Univ Fac Mech Engn & Mech Ningbo Peoples R China Romanian Acad Robot & Mechatron Dept Inst Solid Mech Bucharest Romania Hebei Univ Technol Hebei Key Lab Robot Sensing & Human Robot Interac Tianjin Peoples R China Yanshan Univ Minist Educ Parallel Robot & Mechatron Syst Lab Hebei Prov & Key Lab Adv Forging & Stamping Techn Qinhuangdao Hebei Peoples R China

ISBN: (纸本)9781728199283

At present, the number of patients with lower extremity dysfunction is increasing year by year. However, traditional rehabilitation training cannot meet the needs of patients for rehabilitation training. Rehabilitation robot is a good solution to train patients instead of the rehabilitation physician. Based on clinical practice experience, a lower limb rehabilitation training system based on virtual reality (VR) is designed, which combined the VR technology and rehabilitation evaluation program to improve the rehabilitation efficiency of patients. According to the functional requirements of the lower limb rehabilitation robot (LLR-RO), the construction of rehabilitation robot control system and sensor system is completed. Based on the Unity3D development environment, a VR scenes of space shooting is planned and created for rehabilitation training VR technology which enables patients to complete the training process while maintaining a pleasant mood. Through the software and hardware debugging, the feasibility, data transmission capability of VR-based remote rehabilitation training system and the synchronization performance of VR scenes and rehabilitation robots are verified. In the future, more virtual reality scenes will be studied to adapt to patients of different genders and ages.

关键词： lower limb rehabilitation robot virtual reality space shooting synchronization performance

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Portable Dielectrophoresis Microfluidic Chip Integrated With Microscopic Platform for Water Blooms Monitoring

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JOURNAL OF MICROELECTROMECHANICAL SYSTEMS 2021年第3期30卷 419-425页

作者： Meng, Jiyu Li, Shanshan Yu, Chengzhuang Cheng, Jingmeng Dai, Shijie Wei, Chunyang Li, Junwei Hebei Univ Technol Sch Mech Engn Tianjin 300130 Peoples R China Hebei Univ Technol Hebei Key Lab Robot Sensing & Human Robot Interac Tianjin 300132 Peoples R China Jiangnan Univ Jiangsu Key Lab Adv Mfg Equipment & Technol Wuxi 214122 Jiangsu Peoples R China Hebei Univ Technol Dept Comp Sci & Elect Engn Langfang 065000 Peoples R China Hebei Univ Technol Sch Sci Inst Biophys Tianjin 300401 Peoples R China

Microalgae concentrations have been studied as an important factor to reflect water qualities. High concentration of microalgae should cause water eutrophication then cause environment pollution. However, conventional methods to monitor algal concentration in source water whose use is hampered by high-cost, complicated operation and the need of a centralized laboratory for practical samples' analysis. In order to overcome these constraints, here in this work, we developed a portable and real-time monitoring platform which consists of a microfluidic chip for algae enrichment, a portable microscopic imaging system integrated with a commercial smartphone. The chip is designed and fabricated with a multi-layer electrode structure to trap algaes via alternating current electrokinetics (ACEK) effect. A temperature dependent fully coupled numerical model is presented to calculate the ACEK flow, showing satisfied trapping performance by adjusting the applied voltage and frequency. Moreover, preliminary experiments are performed in our chip using freshwater samples, in which algae trapping behavior is visually observed and recorded by a self-designed portable microscope. Then the trapping performance of this system can be semi-quantitatively figured out by image processing. This lab-on-a-chip system shows high potential in concentrating bio-particles and developing a portable, integrated and automated system for monitoring the quality of water resources in nature. [2020-0381]

关键词： Electrodes Water resources Algae Indium tin oxide Microscopy Mathematical model Monitoring Microalgae enrichment ACEK microscope water quality monitoring

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