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High speed linear motor with low thrust ripple is one of the research focuses of high performance systems. This paper proposes a novel secondary topology for Permanent Magnet Linear Synchronous Motor (PMLSM) with high speed, to suppress the thrust ripple. Permanent magnet (PM) width modulation secondary adopts several PMs to excite the main magnetic field per pole. The issues from a big pole pitch which is generally used by high-speed PMLSM, are solved. These PMs have various longitudinal lengths based on the pulse width modulation principle, to achieve a magnetic field with excellent sinusoidal features. First, the topology structure of PM width modulation secondary is designed. The analytical model of the main magnetic field excited by PMs in this novel secondary is established, the electromagnetic thrust is calculated. Furthermore, the influences of PM width modulation secondary on the main magnetic field and thrust properties are analyzed. The comparisons between two PMLSMs employing PM width modulation secondary and Halbach secondary respectively, are provided. Finally, prototypes are manufactured and tested, to verify the effectiveness of the topology proposed in this research.

Optoelectronic packaging is an important component of optical communication systems. However, it is a challenge for the packaging equipment to simultaneously have multiple degrees of freedom (DOF), wide range, and high precision. In this article, a six-degree-of-freedom (6-DOF) compliant parallel platform with all these features is presented. This platform has a parallel basic structure with large-stroke flexible joints. Based on elastokinematic analysis, the inverse kinematics solution of the platform is derived, and the effectiveness of the platform is proved by analyzing the 6-DOF motion via finite element analysis. The reachable workspace of the platform is analyzed, and its solution process is simplified using the inverse distance weighted method. Furthermore, a prototype of the proposed platform is presented and its accuracy is evaluated through experiments. Error compensation is used to significantly improve the motion accuracy of the platform. A closed-loop control that uses optical power meters instead of a multi-DOF detection device is proposed for optoelectronic packaging. The performance of the prototype applied to the packaging of coaxial optoelectronic devices is also demonstrated by experiments. The results demonstrate that the 6-DOF compliant parallel platform can successfully carry out the optical alignment of optoelectronic devices.

In order to solve the problem of high measurement cost and complex operation of position-independent geometric errors (PIGEs) calibration on a five-axis motion platform, this paper first proposes a low-cost pose measurement method, based on monocular vision, which can accurately determine the pose in the environment, even with image shadow and noise. Next, an improved method, combining pose measurement and kinematic parameters identification, is proposed to calibrate a five-axis motion platform. The kinematic error model of the platform and the pose planning of automatic image acquisition are established, providing the pose data and motor position data, required for calibration. Combined with the kinematic loop method, the kinematic parameters of the five-axis motion platform are identified, while the geometric structure parameters are accurately calibrated. Before and after calibration, a circular trajectory of the target coordinate system (TCS) origin, relative to the camera coordinate system (CCS), is used to test the comprehensive accuracy evolution of the five-axis motion platform, by comparing the position and orientation errors of the theoretical circle trajectory to the actual one. The experimental data show that, before and after calibration, the average position error of the five-axis motion platform is reduced by 79.46%, while the average direction error is reduced by 86.53%. The experimental results clearly demonstrate that the proposed calibration method significantly improves the comprehensive motion accuracy of the five-axis motion platform, and they verify the practical value and effectiveness of the calibration scheme.

This paper investigated the thermal stress distribution in laser welding of Ti6Al4V and 2024-T4 alloys using the coupled thermal–mechanical model based on the thermo-elastoplastic theory. The microstructure and hardness of the dissimilar joint were analyzed based on the simulated results. The asymmetry of temperature and stress distribution indicated that the great difference of material properties had significant effects on the uniformity of thermal stress distribution. The combination of experiment and simulation demonstrated that the growth of grains in heat-affected zone and fusion zone was closely related to the thermal cycle process. The good agreement between the simulated and experimental results verified the rationality of the combined heat source model of double ellipsoid and rotating Gaussian body. The coupled model and simulated results could offer the instructive information in laser welding for other dissimilar alloys.

In this study, a highly reliable and effective method for copper bonding using femtosecond laser-fabricated microscale tapers array and Ag–Zn–Cu intermetallic compounds as assistants is proposed. By the growth of intermetallic compounds among the microscale tapers array, the copper interfaces were firmly sintered. The cross section after shearing test was marked for analysis of sintering quality. Also, the shearing strength of interconnected copper interfaces under different bonding temperature, and holding times was investigated. The results show that the shearing strength can reach up to 120.1 MPa under 300 °C bonding temperature and 30 min holding time. According to the interconnected cross section and shearing strength test, the mechanism of increased shearing strength is explained. The experimental results show that the shearing strength of interconnected interface is greatly enhanced by the increase of contact area caused by microscale tapers array and the mechanical locking caused by the growth of intermetallic compounds. More possibilities could be provided by this technology in the field of electronic packaging interconnection and three-dimensional integrated circuits.

The Footprint of Uncertainty (FOU) for an Interval type-2 (IT2) input fuzzy set is a key parameter of IT2 fuzzy PI and PD (FPI and FPD) controllers because it provides additional options to handle uncertainties. Because the effects of FOUs on IT2 FPI and FPD controller are still unclear, it is necessary to provide a guideline for designing the FOUs. In this study, from the input–output relationship of IT2 FPI and FPD controllers using typical and popular configuration, the variation trend of variable gains, in relation to the increase of FOUs, was analyzed. It is mathematically proven that variable gains of typical controllers decrease or not increase as the FOUs increase. These theoretical results can be extended to provide a guideline for designing FOUs of typical IT2 FPI and FPD controllers. Real-time response of linear voice coil motor is used to show the effectiveness of our results.

With the development of high performance processing system, high precision Permanent Magnet Linear Synchronous Motor (PMLSM) has been the focus of research. This paper provides a novel double-sided PMLSM with quasi- sinusoidal ring windings, to reduce the thrust ripple while keep the average thrust at a suitable value. Firstly, the distributions of the magnetic fields in this motor are analyzed, the low-order harmonics of armature magnetic field induced by the quasi- sinusoidal ring windings are studied, by equivalent magnetizing current (EMC) method. The winding factor and the Back Electromagnetic Force of this PMLSM are analyzed theoretically and verified by finite-element (FEM) method, based on the specific structure of quasi-sinusoidal ring windings. Furthermore, the electromagnetic thrust analysis is provided, which is aimed at the influence of the novel winding structure. Finally, a prototype of the double-sided PMLSM with quasi-sinusoidal ring windings is manufactured to verify the effectiveness of the topology proposed in this research. The presented results show that this novel motor can provide a great thrust property, it has a potential in high performance industry applications.

The study to obtain a sound joint between aluminum and steel is rather challenging due to the large mismatch in thermal properties and the formation of brittle IMCs, especially for press-hardened steel attributing to its martensite microstructure. In this present study, dissimilar joining of 5052 aluminum and press-hardened steel was comprehensively explored by employing laser offset welding without any fillers and interlayers. The influence of laser offset on welding appearance and mechanical properties was evaluated. The microstructure analysis, bonding mechanism, and fracture behavior were identified and characterized by means of optical microscope (OM), scanning electron microscope (SEM), energy-dispersive X-ray spectrometer (EDS), and X-ray diffraction (XRD). The satisfactory welding appearance and mechanical property of 129.6 MPa was obtained at the laser offset of 0.2 mm. The interface microstructure was composed of continuous Fe2Al5, acicular Fe4Al13 and islands IMCs. In addition, micro cracks could be initiated spontaneously in Fe2Al5 layer due to the residual stress, whereas a consecutive crack seems be induced by a micro pore defect. No matter what the fracture mode was during tensile test, the fracture surface was localized at the welded interface.

Cylindrical vibratory gyroscope is a kind of mode-matched gyros, and the frequency split would affect its sensitivity significantly. Frequency tuning is a major method to decrease the split. In the process of frequency tuning, the natural frequency should be measured firstly, and the measurement error is one of the decisive factor of tuning accuracy. Due to the measurement error of frequency is Normal Distribution, its effects on frequency tuning are studied by theoretical and simulation analysis from the statistical aspect. Firstly, the influence of frequency splitting on gyro sensitivity is studied, which shows the importance of reducing frequency splitting. Then the effect of different measuring accuracy on the measured value is analyzed. Thirdly, the tuning error that caused by the measurement error is researched in the process of trimming, and the tuning error is derived by theoretical analysis. Simulation and experiment results under different measurement error exemplify the value of tuning error. Finally, the optimal measurement accuracy that ensures achieving tuning accuracy is discussed.

Beam shaping is required for semiconductor lasers to achieve high optical fiber coupling efficiency in many applications. But the positioning errors on optics may reduce beam shaping effects, and then lead to low optical fiber coupling efficiency. In this work, the positioning errors models for the single emitter laser diode beam shaping system are established. Moreover, the relationships between the errors and the beam shaping effect of each shapers are analysed. Subsequently, the relationship between the errors and the optical fiber coupling efficiency is analysed. The result shows that position errors in the Z axis direction on the fast axis collimator have the greatest influence on the shaping effect, followed by the position errors in the Z axis direction on the converging lens, which should be strictly suppressed in actual operation. Besides, the position errors have a significant influence on the optical fiber coupling efficiency and need to be avoided.

Precision linear motion is widely used in industrial application. For precision linear motion actuators, ripples of thrust force can deteriorate the driving performance and increase mechanical vibrations. It is very important to precisely test the thrust force of a linear motion actuator. This paper proposes a novel method based on testing reaction force and on the aerostatic method to achieve high-precision and universal testing capability. In this method, the mover and the stator of tested linear motion actuators are suspended by two air-bearing modules. In contrast to traditional testing methods, the force sensor is connected to the stator to avoid the influence of vibration on the sensor. The air-bearing modules eliminate the friction between the stator and the mover, so that it would not affect the results. To validate the strategy, a sample testing platform is manufactured, then a series of experiments is carried out, and the testing performance is compared with that of the traditional method. Experimental results demonstrate the high accuracy achieved by eliminating interferences due to friction and the vibration of the force sensor.

A novel fiber inline Mach-Zehnder interferometer (MZI) is proposed for simultaneous measurement of curvature and temperature. The sensor composes of single mode-multimode-dispersion compensation-multimode-single mode fiber (MMF-DCF-MMF) structure, using the direct fusion technology. The experimental results show curvature sensitivities of −12.82 nm/m−1 and −14.42 nm/m−1 in the range of 0–0.65 m−1 for two resonant dips, as well as temperature sensitivities of 57.6 pm/°C and 74.3 pm/°C within the range of 20 °C–150 °C. In addition, the sensor has unique advantages of easy fabrication, low cost, high fringe visibility of 24dB, and high sensitivity, which shows a good application prospect in dual-parameters of sensing of curvature and temperature.

In order to diminish the occurrence of cavitation bubbles during the liquid-assisted laser machining, ultrasound-assisted underwater femtosecond laser drilling on stainless steel is adopted. This method greatly diminishes the optical disturbance of cavitation bubbles. By investigating and analyzing the effect of laser pulse energy and pulse number on the morphology of the holes, it has been found that ultrasound not only has a remarkable function of forming a hole with clean and flat bottom, but also reduces debris redeposition around the processing area. This method improves the machining quality. Besides, it also improves the depth-to-diameter ratio of the hole about 20%.

Efficient coupling of micro/nano-optical waveguides with single-mode fibers is the premise for the efficient operation of the integrated photonic chip, which directly determines its optical performance. In this paper, the design principles of periodically segmented waveguide (PSW) structure used for high-efficiency fiber-chip coupling are proposed, and the effects of refractive index difference Δ on coupling efficiency and structural parameters are studied by simulation. It is found that as the Δ of the PSW increases, the period of the PSW tends to be smaller, and the coupling efficiency decreases continuously, reduced by around 0.673 dB in the range of Δ = 3% to Δ = 7%. Through the analysis of PSW optical mechanisms, it demonstrates that the main reason for the decrease of coupling efficiency is that the transmission loss of the tapered section increases sharply with the increase of Δ. High-Δ PSW is difficult to apply to highly integrated silica optical chips due to the unignorably insertion loss.

Background: Oxycodone is an opioid medication used for the treatment of pain in cancer patients. However, little is known on the direct effects of oxycodone on cancer cells. Aim: To determine the effects and mechanisms of oxycodone in cancer cells. Materials and Methods: Proliferation, survival and migration assays were performed on multiple types of cancer cells. Epithelial growth factor receptor (EGFR)/ERK/Akt pathway and oxidative stress were investigated after oxycodone treatment. Results: Oxycodone can either stimulate growth and migration without affecting survival in MDA-468 cells or inhibit growth and survival without affecting migration in SKBR3 and Caco2 cells. In addition, oxycodone can either attenuate or stimulate efficacy of chemotherapeutic drugs in cancer, depending on the type of cancer cells and nature of action of oxycodone as single drug alone. Our mechanism studies suggest that the stimulatory and inhibitory effects of oxycodone are associated with EGFR expression levels in cancer cells. In cancer cells with high EGFR level, oxycodone activates EGFR signaling in cancer cells, leading to stimulatory effects in multiple biological activities, and this is dependent on opioid receptor. In cancer cells with low EGFR level, oxycodone induces mitochondria-mediated caspase activity and oxidative stress and damage, leading to cell death. Conclusions: Our work is the first to demonstrate systematic analysis of oxycodone’s effects and mechanism of action in cancer. The activation of EGFR signaling by oxycodone may provide a new guide in the clinical use of oxycodone, in particular for cancer patients with high EGFR levels.

A conical microlens on the tip of a fiber for improving the coupling efficiency (CE) of a laser diode and a single-mode fiber in butterfly packaging was experimentally fabricated via the grinding and polishing method and theoretically designed using the beam propagation method. The CE, varying with working distance, was explored under all kinds of optical coupling system parameters, such as incident wavelength, laser beam waist radius, numerical aperture of the fiber, refractive index, and diameter of the microlens. The optimal working distance for the maximal CE was located at approximately 15 μm, proving that the conical-tip coupling was a tight packaging type. Therefore, the CE trends under misalignment and tolerance adjustments could be explained by the spherical aberration theory and light-gathering ability of the microlens. The results are useful in optimum launch optics for designing and fabricating microlens tips on coupled packaging of optoelectronic devices.

Glass products with high joint strength are highly demanded in the field of microelectromechanical system (MEMS). While the quality requirement of MEMS is getting higher and higher, much attention has been paid to further improving the welding strength of the glass. Herein, a femtosecond laser welding method assisted by silver nanofilm for quartz glass is proposed. To optimize the welding results, the influence of the laser power on the location of the heat-affected zone is studied. The effect of coated silver nanofilm at the interface of two glass substrates on femtosecond laser absorptivity is conducted. Also, the welding spot size under different irradiation periods is investigated. In addition, the welding strength with and without the silver nanofilm is measured and compared. It is demonstrated that the welding strength was increased nearly 20% on average by our proposed method compared with direct femtosecond laser welding. In addition, even at the lower laser power than the welding threshold, the welding process could be realized by the proposed method.

A novel bi-piezoelectric jet dispenser with a zoom mechanism is proposed to distribute adhesives rapidly. The work frequency of the new jet dispenser can reach 500 Hz. The volume of the minimum dot is about 25 nL, and the volume error among dots is not more than ±10%. The dot size can be controlled by adjusting the driving voltage of the piezoelectric stack, filling pressure, and the opening time of the valve. Subsystem physical models of the jet valve are presented on the basis of the bi-piezoelectric principle and the zoom mechanism, which involves an electromechanical model, dynamic model, and fluid–solid coupling model. Based on these physical models, a coupled mechanical–electrical fluid simulation model is established, which can be simulated. The simulation results of the multiphysics-coupled model are in accordance with the experiment. The coupling model will develop a reliable simulating platform for high-speed fluid jet. The effectiveness of the bi-piezoelectric method and models is confirmed, and it will provide a new technology for microelectronics packaging.

The core device of dense wavelength division multiplexing (DWDM) system is a wavelength division multiplexer/demultiplexer, among which the arrayed waveguide grating (AWG) device has the most superior optical performances. The optical performances of AWG are mainly affected by the structure parameters such as the waveguide spacing, the width and length of the tapered waveguide and the number of arrayed waveguides. Taking the 40-channel AWG as the research object, by combining theory with simulation, this paper analyzed the influence mechanisms and laws of AWG structure parameters on its optical performances including insertion loss, loss non-uniformity, adjacent crosstalk, and 3 dB bandwidth. Then, the sensitivities analysis of AWG optical performance was carried out by using the direct derivation method and the finite difference method in the sensitivities analysis method, so as to obtain the influence degree of each structure parameter on the optical performances. Finally, based on the influence rules and sensitivities of structure parameters on optical performances, this paper adopted some methods to optimize the structure parameters of AWG, and optimized the insertion loss, loss non-uniformity, adjacent crosstalk, and 3 dB bandwidth to about 1 dB, 0.35 dB, −30 dB, and 0.42 nm, respectively. The research methods and conclusions of this paper can provide references for the optimization of optical performances and layout design of other types of AWG.

Most industrial systems are non-linear and prone to different sources of uncertainties. Accordingly, data generated by these systems for their model development can contain noise and outliers, which consecutively affect the approximation accuracy of their models. Hence, there is a need to use robust approaches, such as fuzzy systems. The type-2 fuzzy system is characterized by a foot print of uncertainty (FOU), which enables it to handle the impreciseness in non-linear systems. In this paper, a strategy for optimizing the membership function (MF) parameters of an interval type-2 fuzzy system using the Kalman gain and error covariance of its constant consequent parameter is presented. In the proposed strategy, the MF parameters are not a part of the input to the extended Kalman filter (EKF) algorithm, which reduces the computational cost of optimization. The proposed strategy was used to identify a robot hand path, Mackey–Glass Chaotic Series, dynamic system, and the inverse kinematics of a 6-PSS parallel robot. The proposed strategy was compared with an interval type-2 fuzzy system having only the consequent parameters being optimized by the extended Kalman filter (KFT2FS). The performance characteristic considered was the root mean square error between the desired output and the model output. The comparison results showed that the proposed model outperformed the KFT2FS, with an improved performance of 85%, 15.7%, 11.25%, and 3.6% for the robot hand path, Mackey–Glass Chaotic Series, dynamic system, and 6-PSS parallel robot respectively and also 7.3%, 17.5%, and 37.1% for 20 dB, 15 dB, and 10 dB corrupted 6-PSS parallel robot data respectively.

The oil containing a small amount of water droplets have induced serious operation malfunctions for precision industrial equipment and even brought fatal disasters, which have aroused widespread concern. However, developing an effective strategy for removal of water from oil is still an enormous challenge. Here, we present a rapid and facile method for fabricating underoil superhydrophilic surface by one-step femtosecond laser direct writing technology. Interestingly, two extreme underoil wettability statuses can be achieved through tuning the scanning velocity (V). Concretely, the pristine underoil hydrophobic titanium sheet will become underoil superhydrophilicity when V is 0.1 m/s, while it will exhibit underoil superhydrophobicity when V increases to 3 m/s. Moreover, the underoil superhydrophilic surface shows excellent water absorption, which could realize the purification of oil contains water droplets regardless of the oil types, and the corresponding mechanism is propounded. We believe that femtosecond laser micromachining has tremendous superiority in solving the problem of oil containing water droplets.

Frequency split is the frequency difference between the driving mode and sensing mode of a vibratory gyroscope, which significantly influences the performance of cylindrical vibratory gyroscopes. In order to reducing frequency split, a method of trimming by drilling micro-holes through laser has been introduced in this paper. Firstly, the processing method of the trimming hole is determined by the finite element simulation, and then the feasibility of the method is verified by the experiment. In the experiment, the frequency split of gyroscope is reduced from 2.090Hz to 0.119Hz.

We demonstrated a fiber in-line Mach-Zehnder interferometer (MZI) coated with platinum (Pt) for the simultaneous measurement of strain and temperature. The sensor was fabricated by splicing a section of multimode fiber (MMF) between two single mode fibers (SMFs) and the Pt coating was prepared by iron sputtering technology. Fine interference fringes of over 20 dB with a compact size of 20 mm were achieved. The experimental results of the two different resonant dips showed strain sensitivities of &minus, 2.06 pm/&mu, &epsilon, and &minus, 2.21 pm/&mu, as well as temperature sensitivities of 55.2 pm/&deg, C and 53.4 pm/&deg, C, respectively. Furthermore, it was found that the Pt coating can improve the strain sensitivity significantly, resulting in an increase of about 54.5%. In addition, the sensor has advantages of easy fabrication, low cost, and high sensitivity, showing great potential for the dual-parameter sensing of strain and temperature.

We have proposed a high sensitive photonic crystal fiber (PCF) strain sensor based on the Mach-Zehnder interferometer (MZI). The sensing head is formed by all-fiber in-line single mode-multimode-photonic-crystal-single mode fiber (SMPS) structure, using only the splicing method. Such a strain sensor exhibited a high sensitivity of −2.21 pm/με within a large measurement range of up to 5000 με and a large fringe visibility of up to 24 dB. Moreover, it was found that the strain sensitivity was weekly dependent of the length of PCF or MMF. In addition, the sensor exhibited the advantages of simplicity of fabrication, high sensitivity and larger fringe visibility.