• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.446-452
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• 2005

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step by step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes a voltage control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.543-550
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• 2005

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step by step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes an adaptive control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1438-1445
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• 2002

For robotic endoscope, some researchers suggest pneumatic actuators based on inchworm motion. But, the existing endoscopes have not been replaced completely because human intestine is very sensitive and susceptible to damage. We design and test a new locomotion of robotic endoscope that allows safe maneuverability in the human intestine. The actuating mechanism is composed of two solenoids at each side and a single permanent magnet. When the current direction is reversed, repulsive force and attractive at the opposition side propels permanent magnet. Impact force against robotic endoscope transfers momentum from moving magnet to endoscope capsule. The direction and moving speed of the actuator can be controlled by adjustment of impact force. Modeling and simulation experiments are carried out to predict the performance of the actuator. Simulations show that force profile of permanent magnet is the dominant factor for the characteristic of the actuator. The results of simulations are verified by comparing with the experimental results.

• Transactions of the Society of Information Storage Systems
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• v.2 no.4
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• pp.251-256
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• 2006

There is a great demand of micro-actuators for mobile information devices such as SFF optical drives and mobile phone cameras. However, the magnetic coils used in conventional electromagnetic motors are a major obstacle for the miniaturization because of their complicated structures and large power consumption. In this paper, a linear ultrasonic motor to actuate focusing lens of mobile devices is proposed. The new actuator uses a ring type bimorph piezoelectric material, and $d_{31}$ mode is adopted for applying linear motion. The interaction between inertia force and friction force makes linear motion by high-frequency saw signal input. The saw signal gives steady forces on the one direction by asymmetric inclination property of the signal itself on time domain. A commercial FEM(ANSYS) was used in this investigation for simulating structural analysis, identification of dynamic property, such as resultant displacement and coupled analysis with piezoelectric material. To evaluate the performance of the new design, a prototype was manufactured and experiments were carried out. Experimental results show the actuator motion of 5.4 mm/s at 10V saw signal of 41 kHz.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.295-300
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• 2001

In recent years, as changing the habit of eating, the pathology in the colon grows up annually. For that reason, the colonoscopy is generalized. But it requires much time to acquire a dexterous skill to perform an operation. And the procedure is painful to the patient. Therefore, biomedical and robotic researchers are developing a locomotive colonoscope that can travel safely in colon. In this paper, we propose a novel design and concept of semi-autonomous colonoscope and two actuators for the micro robot. The micro robot comprises camera and LED for diagnosis, steering system to pass through the loop, pneumatic actuator and bow-shaped flexible supporters to control a contact force and to keep the space between colon wall and the actuator. For actuating mechanism, we suggest two models. One is based on the reaction force, and the other is impact force. In order to validate the concept and the performance of the actuators, we carried out the preliminary experiments in rigid pipes.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2524-2528
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• 2003

High-precision position system is widely used in lots of fields such as semiconductor industry, biotechnology, display and other up-to-date industry field. One of the main issues is to have a long traveling range with precision. There are a few solutions. For instance, there are inchworm methods, lever principle. In this study, we use lever principle to amplify output displacement with a new mechanical amplification structure. We designed new type 3DOF stage with PZT actuator and capacitive sensor. Non-monolithic structure is suggested to obtain the convenience of assembly and modification. Driving parts are designed as modules that generate displacement amplification of each axis. Designed motion module consists of 3 flexure hinges and a PZT actuator with double L lever structure.

• Composites Research
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• v.28 no.2
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• pp.52-57
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• 2015

Soft morphing robotics making use of smart material and based on biomimetic principles are capable of continuous locomotion in harmony with its environment. Since these robots do not use traditional mechanical components, they can be built to be light weight and capable of a diverse range of locomotion. This paper illustrates a flexible smart phone robot made of smart soft composite (SSC) with inchworm-like locomotion capable of two-way linear motion. Since rigid components are embedded within the robot, bending actuators with embedded rigid segments were investigated in order to obtain the maximum bending curvature. To verify the results, a simple mechanical model of this actuator was built and compared with experimental data. After that, the flexible robot was implemented as part of a smart phone robot where the rigid components of the phone were embedded within the matrix. Then, experiments were conducted to test the smart phone robot actuation force under different deflections to verify its load carrying capability. After that, the communication between the smart phone and robot controller was implemented and a corresponding phone application was developed. The locomotion of the smart phone robot actuated through an independent controller was also tested.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.4
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• pp.345-350
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• 2002

In recent years, as changing the habit of eating, the pathology in the colon grows up annually. The colonoscopy is generalized, but if requires much time to acquire a dexterous skill to perform an operation and the procedure is painful to the patient. biomedical and robotic researchers are developing a locomotive colonoscope that can travel safe1y in colon. In this paper, we propose a new actuator and concept of semi-autonomous colonoscope. The micro robot comprises camera and LED for diagnosis, steer- ing system to pass through the loop, pneumatic actuator and bow-shaped flexible supporters to control a contact force and to pass over haustral folds in colon. For locomotion of semi-autonomous colonoscope, we suggest an actuator that is based on impact force between a cylinder and a piston. In order to validate the concept and the performance of the actuator, we carried out the simulation of moving characteristics and the preliminary experiments in rigid pipes and on the colon of pig.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.99-104
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• 2004

Micro/meso cutting is getting more important in the fields of precision machining technology. A micro-turning lathe is one of parts to consist the Micro Factory. It accepts stepwise motion actuators that are used for feeding system instead of the conventional mechanism. It is consisted of two Piezoelectric ceramics; one is for feeding the slider, and the other is for clamping the slider in the guide way of the body. The linearity and positional accuracy of the actuators are good enough for high precision motion. The spindle unit is operated with DC motor on the top of the slider. The motion is communicated with miniaturized linear encoder attached on each side of axis. A mono crystal diamond tool is used for cutting tool. This micro-lathe has been made a machining experiment to see the characteristics of micro-machining.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1203-1206
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• 2003

After the micro turning lathe was developed in the last year by AMR Laboratory, a micro-milling machine is developed for micro machining. This machine is integrated with PZT-driven micro-sliders, micro-linear encoders, air turbine spindle which has maximum 150.000 rpm. It is applicable to milling and drilling machining. This paper shows the possibility of micro machining and characteristics of micro end milling process by using micro machine. A machining of micro barrier ribs using 0.2 mm flat type end mill was achieved by micro-milling machine. As experimental results show the machining capability and positional accuracy of this machine is good enough for machining micro parts.