Ki-Uk Kyung | Korea Advanced Institute of Science and Technology (original) (raw)

Papers by Ki-Uk Kyung

Research paper thumbnail of Wrist Assisting Soft Wearable Robot with Stretchable Coolant Vessel integrated SMA Muscle

IEEE/ASME Transactions on Mechatronics

Research paper thumbnail of Electroadhesion based High-Payload Soft Gripper with Mechanically Strengthened Structure

IEEE Transactions on Industrial Electronics

Research paper thumbnail of A Wearable Soft Tactile Actuator With High Output Force for Fingertip Interaction

IEEE Access

This paper reports a soft fingertip-mountable tactile actuator based on a Dielectric Elastomer Ac... more This paper reports a soft fingertip-mountable tactile actuator based on a Dielectric Elastomer Actuator (DEA), which exhibits high output force over a wide frequency range with a lightweight and soft structure. DEA is a soft actuator characterized by its large area strain, fast response speed, and high specific energy density. The proposed soft tactile actuator is constructed of a multi-layered conical DEA structure. This design has safety benefits because it isolates the high voltage components from the contact point. In this paper, the resonance frequency of the tactile actuator was designed to be at 250 Hz to maximize vibrotactile stimulation. In addition, the geometric design parameters of the soft tactile actuator were optimized by conducting the simulations and the experiments. Based on these efforts, the proposed actuator produces a high output force of 8.48 N at the resonance frequency, with a maximum displacement of 0.46 mm. Our wearable prototype was an entirely soft haptic system, which exhibits high output force, as well as flexibility and conformity with a total weight of 2.6 g. INDEX TERMS Haptic interfaces, intelligent actuators, human robot interaction, soft robotics.

Research paper thumbnail of Dielectric Elastomer Actuator for Soft Robotics Applications and Challenges

Applied Sciences

This paper reviews state-of-the-art dielectric elastomer actuators (DEAs) and their future perspe... more This paper reviews state-of-the-art dielectric elastomer actuators (DEAs) and their future perspectives as soft actuators which have recently been considered as a key power generation component for soft robots. This paper begins with the introduction of the working principle of the dielectric elastomer actuators. Because the operation of DEA includes the physics of both mechanical viscoelastic properties and dielectric characteristics, we describe theoretical modeling methods for the DEA before introducing applications. In addition, the design of artificial muscles based on DEA is also introduced. This paper reviews four popular subjects for the application of DEA: soft robot hand, locomotion robots, wearable devices, and tunable optical components. Other potential applications and challenging issues are described in the conclusion.

Research paper thumbnail of A piecewise controllable tunable lens with large aperture for eyewear application

Smart Materials and Structures

Research paper thumbnail of Design of Shape Memory Alloy-Based Soft Wearable Robot for Assisting Wrist Motion

Applied Sciences

In this paper, we propose a shape memory alloy (SMA)-based wearable robot that assists the wrist ... more In this paper, we propose a shape memory alloy (SMA)-based wearable robot that assists the wrist motion for patients who have difficulties in manipulating the lower arm. Since SMA shows high contraction strain when it is designed as a form of coil spring shape, the proposed muscle-like actuator was designed after optimizing the spring parameters. The fabricated actuator shows a maximum force of 10 N and a maximum contraction ratio of 40%. The SMA-based wearable robot, named soft wrist assist (SWA), assists 2 degrees of freedom (DOF) wrist motions. In addition, the robot is totally flexible and weighs 151g for the wearable parts. A maximum torque of 1.32 Nm was measured for wrist flexion, and a torque of larger than 0.5 Nm was measured for the other motions. The robot showed the average range of motion (ROM) with 33.8, 30.4, 15.4, and 21.4 degrees for flexion, extension, ulnar, and radial deviation, respectively. Thanks to the soft feature of the SWA, time cost for wearing the device...

Research paper thumbnail of A soft and transparent visuo-haptic interface pursuing wearable devices

IEEE Transactions on Industrial Electronics

Research paper thumbnail of A Robust Soft Lens for Tunable Camera Application Using Dielectric Elastomer Actuators

Research paper thumbnail of Applications of Smart Materials to Haptics

IEEE Transactions on Haptics

Research paper thumbnail of Electro-Active Polymer Based Soft Tactile Interface for Wearable Devices

IEEE transactions on haptics

This paper reports soft actuator based tactile stimulation interfaces applicable to wearable devi... more This paper reports soft actuator based tactile stimulation interfaces applicable to wearable devices. The soft actuator is prepared by multi-layered accumulation of thin electro-active polymer (EAP) films. The multi-layered actuator is designed to produce electrically-induced convex protrusive deformation, which can be dynamically programmable for wide range of tactile stimuli. The maximum vertical protrusion is and the output force is up to 255 mN. The soft actuators are embedded into the fingertip part of a glove and front part of a forearm band, respectively. We have conducted two kinds of experiments with 15 subjects. Perceived magnitudes of actuator's protrusion and vibrotactile intensity were measured with frequency of 1 Hz and 191 Hz, respectively. Analysis of the user tests shows participants perceive variation of protrusion height at the finger pad and modulation of vibration intensity through the proposed soft actuator based tactile interface.

Research paper thumbnail of A thin film active-lens with translational control for dynamically programmable optical zoom

Research paper thumbnail of Perspective and potential of smart optical materials

Smart Materials and Structures

Research paper thumbnail of An electro-active polymer based lens module for dynamically varying focal system

Research paper thumbnail of Flexible transparent displays based on core/shell upconversion nanophosphor-incorporated polymer waveguides

Scientific reports, Jan 3, 2017

Core/shell (C/S)-structured upconversion nanophosphor (UCNP)-incorporated polymer waveguide-based... more Core/shell (C/S)-structured upconversion nanophosphor (UCNP)-incorporated polymer waveguide-based flexible transparent displays are demonstrated. Bright green- and blue-emitting Li(Gd,Y)F4:Yb,Er and Li(Gd,Y)F4:Yb,Tm UCNPs are synthesized via solution chemical route. Their upconversion luminescence (UCL) intensities are enhanced by the formation of C/S structure with LiYF4 shell. The Li(Gd,Y)F4:Yb,Er/LiYF4 and Li(Gd,Y)F4:Yb,Tm/LiYF4 C/S UCNPs exhibit 3.3 and 2.0 times higher UCL intensities than core counterparts, respectively. In addition, NaGdF4:Yb,Tm/NaGdF4:Eu C/S UCNPs are synthesized and they show red emission via energy transfer and migration of Yb(3+) → Tm(3+) → Gd(3+) → Eu(3+). The C/S UCNPs are incorporated into bisphenol A ethoxylate diacrylate which is used as a core material of polymer waveguides. The fabricated stripe-type polymer waveguides are highly flexible and transparent (transmittance > 90% in spectral range of 443-900 nm). The polymer waveguides exhibit bright...

Research paper thumbnail of High-Performance Flexible Multilayer MoS2Transistors on Solution-Based Polyimide Substrates

Advanced Functional Materials, 2016

Research paper thumbnail of Influence on Deformed Shape of Electrostatic Deformable Mirror by the Geometry of Electrode

Conference on Lasers and Electro-Optics, 2016

Research paper thumbnail of Haptic mouse interface system for providing force and tactile feedbacks to user's fingers and arm

Research paper thumbnail of Structure modulated electrostatic deformable mirror for focus and geometry control

Optics express, Jan 11, 2016

We suggest a way to electrostatically control deformed geometry of an electrostatic deformable mi... more We suggest a way to electrostatically control deformed geometry of an electrostatic deformable mirror (EDM) based on geometric modulation of a basement. The EDM is composed of a metal coated elastomeric membrane (active mirror) and a polymeric basement with electrode (ground). When an electrical voltage is applied across the components, the active mirror deforms toward the stationary basement responding to electrostatic attraction force in an air gap. Since the differentiated gap distance can induce change in electrostatic force distribution between the active mirror and the basement, the EDMs are capable of controlling deformed geometry of the active mirror with different basement structures (concave, flat, and protrusive). The modulation of the deformed geometry leads to significant change in the range of the focal length of the EDMs. Even under dynamic operations, the EDM shows fairly consistent and large deformation enough to change focal length in a wide frequency range (1~175 ...

Research paper thumbnail of Tactile feedback for button GUI on touch devices

Proceedings of the 2012 ACM annual conference extended abstracts on Human Factors in Computing Systems Extended Abstracts - CHI EA '12, 2012

ABSTRACT

Research paper thumbnail of Haptic interface design for future interactive devices

SIGGRAPH Asia 2015 Haptic Media And Contents Design on - SA '15, 2015

Research paper thumbnail of Wrist Assisting Soft Wearable Robot with Stretchable Coolant Vessel integrated SMA Muscle

IEEE/ASME Transactions on Mechatronics

Research paper thumbnail of Electroadhesion based High-Payload Soft Gripper with Mechanically Strengthened Structure

IEEE Transactions on Industrial Electronics

Research paper thumbnail of A Wearable Soft Tactile Actuator With High Output Force for Fingertip Interaction

IEEE Access

This paper reports a soft fingertip-mountable tactile actuator based on a Dielectric Elastomer Ac... more This paper reports a soft fingertip-mountable tactile actuator based on a Dielectric Elastomer Actuator (DEA), which exhibits high output force over a wide frequency range with a lightweight and soft structure. DEA is a soft actuator characterized by its large area strain, fast response speed, and high specific energy density. The proposed soft tactile actuator is constructed of a multi-layered conical DEA structure. This design has safety benefits because it isolates the high voltage components from the contact point. In this paper, the resonance frequency of the tactile actuator was designed to be at 250 Hz to maximize vibrotactile stimulation. In addition, the geometric design parameters of the soft tactile actuator were optimized by conducting the simulations and the experiments. Based on these efforts, the proposed actuator produces a high output force of 8.48 N at the resonance frequency, with a maximum displacement of 0.46 mm. Our wearable prototype was an entirely soft haptic system, which exhibits high output force, as well as flexibility and conformity with a total weight of 2.6 g. INDEX TERMS Haptic interfaces, intelligent actuators, human robot interaction, soft robotics.

Research paper thumbnail of Dielectric Elastomer Actuator for Soft Robotics Applications and Challenges

Applied Sciences

This paper reviews state-of-the-art dielectric elastomer actuators (DEAs) and their future perspe... more This paper reviews state-of-the-art dielectric elastomer actuators (DEAs) and their future perspectives as soft actuators which have recently been considered as a key power generation component for soft robots. This paper begins with the introduction of the working principle of the dielectric elastomer actuators. Because the operation of DEA includes the physics of both mechanical viscoelastic properties and dielectric characteristics, we describe theoretical modeling methods for the DEA before introducing applications. In addition, the design of artificial muscles based on DEA is also introduced. This paper reviews four popular subjects for the application of DEA: soft robot hand, locomotion robots, wearable devices, and tunable optical components. Other potential applications and challenging issues are described in the conclusion.

Research paper thumbnail of A piecewise controllable tunable lens with large aperture for eyewear application

Smart Materials and Structures

Research paper thumbnail of Design of Shape Memory Alloy-Based Soft Wearable Robot for Assisting Wrist Motion

Applied Sciences

In this paper, we propose a shape memory alloy (SMA)-based wearable robot that assists the wrist ... more In this paper, we propose a shape memory alloy (SMA)-based wearable robot that assists the wrist motion for patients who have difficulties in manipulating the lower arm. Since SMA shows high contraction strain when it is designed as a form of coil spring shape, the proposed muscle-like actuator was designed after optimizing the spring parameters. The fabricated actuator shows a maximum force of 10 N and a maximum contraction ratio of 40%. The SMA-based wearable robot, named soft wrist assist (SWA), assists 2 degrees of freedom (DOF) wrist motions. In addition, the robot is totally flexible and weighs 151g for the wearable parts. A maximum torque of 1.32 Nm was measured for wrist flexion, and a torque of larger than 0.5 Nm was measured for the other motions. The robot showed the average range of motion (ROM) with 33.8, 30.4, 15.4, and 21.4 degrees for flexion, extension, ulnar, and radial deviation, respectively. Thanks to the soft feature of the SWA, time cost for wearing the device...

Research paper thumbnail of A soft and transparent visuo-haptic interface pursuing wearable devices

IEEE Transactions on Industrial Electronics

Research paper thumbnail of A Robust Soft Lens for Tunable Camera Application Using Dielectric Elastomer Actuators

Research paper thumbnail of Applications of Smart Materials to Haptics

IEEE Transactions on Haptics

Research paper thumbnail of Electro-Active Polymer Based Soft Tactile Interface for Wearable Devices

IEEE transactions on haptics

This paper reports soft actuator based tactile stimulation interfaces applicable to wearable devi... more This paper reports soft actuator based tactile stimulation interfaces applicable to wearable devices. The soft actuator is prepared by multi-layered accumulation of thin electro-active polymer (EAP) films. The multi-layered actuator is designed to produce electrically-induced convex protrusive deformation, which can be dynamically programmable for wide range of tactile stimuli. The maximum vertical protrusion is and the output force is up to 255 mN. The soft actuators are embedded into the fingertip part of a glove and front part of a forearm band, respectively. We have conducted two kinds of experiments with 15 subjects. Perceived magnitudes of actuator's protrusion and vibrotactile intensity were measured with frequency of 1 Hz and 191 Hz, respectively. Analysis of the user tests shows participants perceive variation of protrusion height at the finger pad and modulation of vibration intensity through the proposed soft actuator based tactile interface.

Research paper thumbnail of A thin film active-lens with translational control for dynamically programmable optical zoom

Research paper thumbnail of Perspective and potential of smart optical materials

Smart Materials and Structures

Research paper thumbnail of An electro-active polymer based lens module for dynamically varying focal system

Research paper thumbnail of Flexible transparent displays based on core/shell upconversion nanophosphor-incorporated polymer waveguides

Scientific reports, Jan 3, 2017

Core/shell (C/S)-structured upconversion nanophosphor (UCNP)-incorporated polymer waveguide-based... more Core/shell (C/S)-structured upconversion nanophosphor (UCNP)-incorporated polymer waveguide-based flexible transparent displays are demonstrated. Bright green- and blue-emitting Li(Gd,Y)F4:Yb,Er and Li(Gd,Y)F4:Yb,Tm UCNPs are synthesized via solution chemical route. Their upconversion luminescence (UCL) intensities are enhanced by the formation of C/S structure with LiYF4 shell. The Li(Gd,Y)F4:Yb,Er/LiYF4 and Li(Gd,Y)F4:Yb,Tm/LiYF4 C/S UCNPs exhibit 3.3 and 2.0 times higher UCL intensities than core counterparts, respectively. In addition, NaGdF4:Yb,Tm/NaGdF4:Eu C/S UCNPs are synthesized and they show red emission via energy transfer and migration of Yb(3+) → Tm(3+) → Gd(3+) → Eu(3+). The C/S UCNPs are incorporated into bisphenol A ethoxylate diacrylate which is used as a core material of polymer waveguides. The fabricated stripe-type polymer waveguides are highly flexible and transparent (transmittance > 90% in spectral range of 443-900 nm). The polymer waveguides exhibit bright...

Research paper thumbnail of High-Performance Flexible Multilayer MoS2Transistors on Solution-Based Polyimide Substrates

Advanced Functional Materials, 2016

Research paper thumbnail of Influence on Deformed Shape of Electrostatic Deformable Mirror by the Geometry of Electrode

Conference on Lasers and Electro-Optics, 2016

Research paper thumbnail of Haptic mouse interface system for providing force and tactile feedbacks to user's fingers and arm

Research paper thumbnail of Structure modulated electrostatic deformable mirror for focus and geometry control

Optics express, Jan 11, 2016

We suggest a way to electrostatically control deformed geometry of an electrostatic deformable mi... more We suggest a way to electrostatically control deformed geometry of an electrostatic deformable mirror (EDM) based on geometric modulation of a basement. The EDM is composed of a metal coated elastomeric membrane (active mirror) and a polymeric basement with electrode (ground). When an electrical voltage is applied across the components, the active mirror deforms toward the stationary basement responding to electrostatic attraction force in an air gap. Since the differentiated gap distance can induce change in electrostatic force distribution between the active mirror and the basement, the EDMs are capable of controlling deformed geometry of the active mirror with different basement structures (concave, flat, and protrusive). The modulation of the deformed geometry leads to significant change in the range of the focal length of the EDMs. Even under dynamic operations, the EDM shows fairly consistent and large deformation enough to change focal length in a wide frequency range (1~175 ...

Research paper thumbnail of Tactile feedback for button GUI on touch devices

Proceedings of the 2012 ACM annual conference extended abstracts on Human Factors in Computing Systems Extended Abstracts - CHI EA '12, 2012

ABSTRACT

Research paper thumbnail of Haptic interface design for future interactive devices

SIGGRAPH Asia 2015 Haptic Media And Contents Design on - SA '15, 2015