Self-Alignment and Bonding of Microparts Using Adhesive Droplets

Kaiji Sato,Keunuk Lee,Masahiko Nishimura,Kazutoshi Okutsu 한국정밀공학회 2007 International Journal of Precision Engineering and Vol.8 No.2

This paper describes the self-alignment and bonding of microparts using adhesive surface tension to assemble microsystems in air. The alignment and bonding were tested experimentally using adhesive droplets, and the resulting performance was evaluated. The adhesive, which was inorganic and water-soluble before hardening, was diluted with water to a ratio of 10:1 so that its surface tension generated a sufficient restoring force for self-alignment. The experimental results showed that the average of the alignment errors obtained using the adhesive on 1.0 × 1.0 × 0.15-㎜ micro parts was less than 2 ㎛ in the X and Y directions and 0.2 degrees in the θ direction. These alignment errors were almost the same as those obtained using water. The use of a suitable adhesive had no negative effects on the alignment accuracy. The average tensile strength of the adhesive bond after self-alignment was 0.61 N/㎟.

High-Speed Positioning of Ultrahigh-Acceleration and High-Velocity Linear Synchronous Motor

Kaiji Sato,Tadashi Hama 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

This paper describes the high-speed positioning of a moving permanent magnet linear synchronous motor (MPM LSM) utilizing itshigh thrust-to-mover mass ratio of 908 N/kg. The MPM LSM was designed to have a high static thrust-to-mover mass ratio for highaccelerationand high-velocity motion However, the MPM LSM has large inductances and large back electromotive force (EMF), bothof which slow down the current response and greatly reduce the available thrust force. Under the limited supply voltage condition,these features deteriorate the response of the MPM LSM, as represented by the acceleration and velocity characteristics. To reducethe effect of the features on the response, a simple and basic dynamic model of the MPM LSM is derived and used in the design ofa phase lead function for the high response. The effectiveness of the phase lead function, which improved the response, is examinedby straight motion and positioning experiments. The high-speed positioning performance is verified by using the control system withthe phase lead function. The experimental response to a step input of 300 mm shows acceleration higher than 500 m/s2, velocity higherthan 7.76 m/s and position error smaller than 2 mm.

Practical Ultraprecision Positioning of a Ball Screw Mechanism

Kaiji Sato,Guilherme Jorge Maeda 한국정밀공학회 2008 International Journal of Precision Engineering and Vol.9 No.2

This paper describes the problem of ultra precision positioning with a ball screw mechanism in the microdynamic range, along with its solution. We compared the characteristics of two ball screw mechanisms with different table masses. The experimental results showed that the vibration resulting from the low stiffness of the ball screw degraded the positioning performance in the microdynamic range for the heavyweight mechanism. The proposed nominal characteristic trajectory following (NCTF) controller was designed for ultra precision positioning of the ball screw mechanism. The basic NCTF control system achieved ultra precision positioning performance with the lightweight mechanism, but not with the heavyweight mechanism. A conditional notch filter was added to the NCTF controller to overcome this problem. Despite the differences in payload and friction, both mechanisms then showed similar positioning performance, demonstrating the high robustness and effectiveness of the improved NCTF controller with the conditional notch filter. The experimental results demonstrated that the improved NCTF control system with the conditional notch filter achieved ultra precision positioning with a positioning accuracy of better than 10 ㎚, independent of the reference step input height.

Self-Alignment and Bonding of Microparts Using Adhesive Droplets

Sato, Kaiji,Lee, Keun-Uk,Nishimura, Masahiko,Okutsu, Kazutoshi Korean Society for Precision Engineering 2007 International Journal of Precision Engineering and Vol.8 No.2

This paper describes the self-alignment and bonding of microparts using adhesive surface tension to assemble microsystems in air. The alignment and bonding were tested experimentally using adhesive droplets, and the resulting performance was evaluated. The adhesive, which was inorganic and water-soluble before hardening, was diluted with water to a ratio of 10:1 so that its surface tension generated a sufficient restoring force for self-alignment. The experimental results showed that the average of the alignment errors obtained using the adhesive on $1.0\times1.0\times0.15-mm$ microparts was less than $2{\mu}m$ in the X and Y directions and 0.2 degrees in the e direction. These alignment errors were almost the same as those obtained using water. The use of a suitable adhesive had no negative effects on the alignment accuracy. The average tensile strength of the adhesive bond after self-alignment was $0.61N/mm^2$.

Advanced two-level CMFD acceleration method for the 3D whole-core high-fidelity neutron adjoint transport calculation

Zhu, Kaijie,Hao, Chen,Xu, Yunlin Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.1

In the 2D/1D method, a global adjoint CMFD based on the generalized equivalence theory is built to synthesize the 2D radial MOC adjoint and 1D axial NEM adjoint calculation and also to accelerate the iteration convergence of 3D whole-core adjoint transport calculation. Even more important, an advanced yet accurate two-level (TL) CMFD acceleration technique is proposed, in which an equivalent one-group adjoint CMFD is established to accelerate the multi-group adjoint CMFD and then to accelerate the 3D whole-core adjoint transport calculation efficiently. Based on these method, a new code is developed to perform 3D adjoint neutron flux calculation. Then a set of VERA and C5G7 benchmark problems are chosen to verify the capability of the 3D adjoint calculations and the effectiveness of TL CMFD acceleration. The numerical results demonstrate that acceptable accuracy of 2D/1D adjoint calculations and superior acceleration of TL CMFD are achievable.

Practical Ultraprecision Positioning of a Ball Screw Mechanism

Sato, Kaiji,Maeda, Guilherme Jorge Korean Society for Precision Engineering 2008 International Journal of Precision Engineering and Vol.9 No.2

This paper describes the problem of ultraprecision positioning with a ball screw mechanism in the microdynamic range, along with its solution. We compared the characteristics of two ball screw mechanisms with different table masses. The experimental results showed that the vibration resulting from the low stiffness of the ball screw degraded the positioning performance in the microdynamic range for the heavyweight mechanism. The proposed nominal characteristic trajectory following (NCTF) controller was designed for ultra precision positioning of the ball screw mechanism. The basic NCTF control system achieved ultra precision positioning performance with the lightweight mechanism, but not with the heavyweight mechanism. A conditional notch filter was added to the NCTF controller to overcome this problem. Despite the differences in payload and friction, both mechanisms then showed similar positioning performance, demonstrating the high robustness and effectiveness of the improved NCTF controller with the conditional notch filter. The experimental results demonstrated that the improved NCTF control system with the conditional notch filter achieved ultra precision positioning with a positioning accuracy of better than 10 nm, independent of the reference step input height.

Novel and Compact Thermomagnetic Actuator Using Temperature-Sensitive Magnetic Materials

Tadashi Hama,Kaiji Sato 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.12

This paper describes the structure and characteristics of a novel compact actuator that uses a combination of temperature-sensitive magnetic materials (TSMMs) and permanent magnets (PMs). The actuator has the potential to generate a large force per volume, while the absence of a coil structure makes it easy to downsize. The structure and driving principles of the actuator were determined to exploit the advantages of this combination, and thrust force characteristics were examined through numerical analysis. The thrust force generated was measured based on the temperature of the TSMMs. The temperature characteristics were investigated experimentally and theoretically. In addition to thrust force, the energy consumption was experimentally examined with respect to the TSMM temperature. The results indicate that the proposed actuator performed better than a conventional electromagnetic actuator in generating a large continuous thrust force.

Wind Power Interval Prediction Based on Improved PSO and BP Neural Network

Jidong Wang,Kaijie Fang,Wenjie Pang,Jiawen Sun 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.3

As is known to all that the output of wind power generation has a character of randomness and volatility because of the influence of natural environment conditions. At present, the research of wind power prediction mainly focuses on point forecasting, which can hardly describe its uncertainty, leading to the fact that its application in practice is low. In this paper, a wind power range prediction model based on the multiple output property of BP neural network is built, and the optimization criterion considering the information of predicted intervals is proposed. Then, improved Particle Swarm Optimization (PSO) algorithm is used to optimize the model. The simulation results of a practical example show that the proposed wind power range prediction model can effectively forecast the output power interval, and provide power grid dispatcher with decision.

A Game Theory Based Interaction Strategy between Residential Users and an Electric Company

Jidong Wang,Kaijie Fang,Yuhao Yang,Yingchen Shi,Daoqiang Xu,Shuangshuang Zhao 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

With the development of smart grid technology, it has become a hotspot to increase benefits of both residential users and electric power companies through demand response technology and interactive technology. In this paper, the game theory is introduced to the interaction between residential users and an electric company, making a mutually beneficial situation for the two. This paper solves the problem of electricity pricing and load shifting in the interactive behavior by building the game-theoretic process, proposing the interaction strategy and doing the optimization. In the simulation results, the residential users decrease their cost by 11% mainly through shifting the thermal loads and the electric company improves its benefits by 5.6% though electricity pricing. Simulation analysis verifies the validity of the proposed method and shows great revenue for the economy of both sides.

Quantum-dot Cellular Automata Design Guideline

Kyosun Kim,Kaijie Wu,Ramesh Karri 대한전자공학회 2005 ITC-CSCC :International Technical Conference on Ci Vol.2005 No.1