• The Journal of Korea Robotics Society
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• v.8 no.3
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• pp.156-163
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• 2013

This paper describes a flexible visuo-haptic display module. We have developed a flexible electro-active polymer (EAP) actuator and a thin flexible visual display with $3{\times}3$ array configuration via polymer technology. The flexible actuator consists of nine EAP cells vertically moving in response to change in their thickness. The flexible display uses polymer based optical waveguide allowing light to scatter only at specific area. The display film is transparent and identically designed to the array pattern to fit for the arrangement of actuator cells. A pressure sensor is installed under the integrated module. The performance of the actuator is proved to be sufficient for satisfying perceivable range of human touch sense. The integrated system can provide interactive haptic feedback such as key pressing, contact vibration sensations, and etc. in accordance with user input.

• The Journal of Korea Robotics Society
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• v.8 no.3
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• pp.150-155
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• 2013

Vibrotactile actuators for small consumer electronic products, such as mobile devices, have been widely used for conveying haptic sensation to users. One of the most important things in vibrotactile actuators is to be developed in the form of thin actuator which can be easily embedded into mobile devices and to provide vibrotactile signals with wide frequency band to users. Thus, this paper proposes a thin film type haptic actuator with an aim to convey vibrotactile information with high frequency bandwidth to users in mobile devices. To this end, a vibrotactile actuator which creates haptic sensation is designed and constructed based on cellulose acetate material. A cellulose acetate material charged with an electric potential can generate vibration under the AC voltage input. It is found that the motion of the actuator can have concave or convex shape by controlling a polarity of both charged membranes and the actuator performance can be modulated by increasing level of biased electric potential. The experiment clearly shows that the proposed actuator creates enough output force to stimulate human skin with a large frequency bandwidth and to simulate various vibrotactile sensations to users.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.395-396
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• 2011

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.693-694
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• 2011

• Composites Research
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• v.25 no.3
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• pp.70-75
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• 2012

Interfacial durability and electrical properties of CNT, ITO or xGnP coated PVDF nanocomposites were investigated for acoustic actuator applications. The xGnP coated PVDF nanocomposite exhibited better electrical conductivity than CNT and ITO case due to the unique electrical property of xGnP, and this nanocomposite also showed good sound characteristics. Interfacial adhesion durability between either neat CNT or plasma treated CNT and plasma treated PVDF were measured by static contact angle, surface energy, work of adhesion, and spreading coefficient tests. The optimum acoustic actuation performance of xGnP coated PVDF nanocomposite was measured using sound level meter with changing radius of curvature and coating conditions. As compared to CNT and ITO, the xGnP was known as more appropriate acoustic actuator due to the characteristic electrical property. It is the most appropriate condition when the radius of curvature is 15 degree. Although sound characteristics were different with various coating thicknesses, it is possible to manufacture transparent actuator with good sound quality.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.8
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• pp.743-748
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• 2015

This paper reports the enhanced fabrication and characterization of a $3{\times}3$ array tactile actuator composed of cellulose acetate. The array tactile actuator, with dimensions of $15{\times}15{\times}1mm^3$, consists of 9 pillar-supported cells made from a cellulose-acetate molding. The fabrication process and performance test along with the results for the suggested actuator are explained. To improve the cell-array fabrication, a laser cut was adopted after the molding process. The displacement of the unit cell increased the input voltage and frequency. Various top masses are added onto the actuator to mimic the touch force, and the acceleration of the actuator is measured under actuation. When 2 kV is applied to the actuator, the maximum acceleration is 0.64 g, which is above the vibrotactile threshold. The actuation mechanism is associated with the electrostatic force between the top and bottom electrodes.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.386.1-386.1
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• 2014

The ionic polymer-metal composite (IPMC), a type of electro-active polymer material, has received enormous interest in various fields such as robotics, medical sensors, artificial muscles because it has many advantages of flexibility, light weight, high displacement, and low voltage activation, compare to traditional mechanical actuators. Mostly noble metal materials such as gold or platinum were used to form the electrode of an IPMC by using electroless plating process. Furthermore, carbon-based materials, which are carbon nanotube (CNT) and reduced graphene-CNT composite, were used to alter the electrode of IPMC. To form the electrode of IPMC, we employ the synthesized graphene on copper foil by chemical vapor deposition method and use the transfer process by using a support of PET/silicone film. The properties of graphene were evaluated by Raman spectroscopy, UV/Vis spectroscopy, and 4-point probe. The structure and surface of IPMC were analyzed via field emission scanning electron microscope. The fabricated IPMC performance such as displacement and operating frequency was measured in underwater.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1028-1033
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• 2005

Robot is composed of various devices but, those are incompatible with each other and hardly developing reusable control software. We suggest standard abstract interface for robot software component to make portable device and reusable control software of robot. This assures uniform abstracted interface to the device driver software like sensor and actuator and, control program can be transparent operation over device. We can develop devices and control software separately and independently with this idea. This makes it possible to replace existing devices with new devices which have a improved performance.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2285-2289
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• 2005

Robot is composed of various devices but, those are incompatible with each other and hardly developing reusable control software. This study suggests standard abstract interface for robot software component to make portable device and reusable control software of robot, based on familiar techniques to abstract device in operating systems. This assures uniform abstracted interface to the device driver software like sensor and actuator and, control program can be transparent operation over device. This study can separately and independently develop devices and control software with this idea. This makes it possible to replace existing devices with new devices which have an improved performance.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1190-1194
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• 2007

Since the dismantling processes of building are very dangerous, there have been many studies to develop a remote operating devices using joystick. In this paper, in order to improve the operability of the dismantling actuator that is usually an excavator, a novel concept of tele-operated haptic device is proposed. Operators who use this haptic device with additional environmental sensing devices can work safely away from the dangerous sites. First, based on the concept design of the haptic device, the workspace mapping from the haptic device to the excavator is explored. Second, the kinematics which deals with the conversion from the 3 dimensional position information of the haptic device to the joint variable information of the backhoe is included. Lastly, 3D graphical simulation of both haptic device and the backhoe will be shown. This new design of the haptic device can be easily manufactured and gives the workers very convenient and transparent remote control capability.