Philseok Kim - Academia.edu (original) (raw)
Papers by Philseok Kim
Conference on Lasers and Electro-Optics 2010, 2010
... Mikhail A. Kats1*, Darren J. Lipomi2, Philseok Kim1, Sung H. Kang1, Joanna Aizenberg1, George... more ... Mikhail A. Kats1*, Darren J. Lipomi2, Philseok Kim1, Sung H. Kang1, Joanna Aizenberg1, George M. Whitesides2, Federico Capasso1 1School of ... We acknowledge Christian Pflugl, RomainBlanchard, and Benjamin Wiley for helpful discussions, as well as support from the ...
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Building and Environment, 2014
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Nanotechnology, Jan 10, 2014
The development of a stain-resistant and pressure-stable textile is desirable for consumer and in... more The development of a stain-resistant and pressure-stable textile is desirable for consumer and industrial applications alike, yet it remains a challenge that current technologies have been unable to fully address. Traditional superhydrophobic surfaces, inspired by the lotus plant, are characterized by two main components: hydrophobic chemical functionalization and surface roughness. While this approach produces water-resistant surfaces, these materials have critical weaknesses that hinder their practical utility, in particular as robust stain-free fabrics. For example, traditional superhydrophobic surfaces fail (i.e., become stained) when exposed to low-surface-tension liquids, under pressure when impacted by a high-velocity stream of water (e.g., rain), and when exposed to physical forces such as abrasion and twisting. We have recently introduced slippery lubricant-infused porous surfaces (SLIPS), a self-healing, pressure-tolerant and omniphobic surface, to address these issues. He...
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Advanced Optical Materials, 2013
ABSTRACT Rational design strategies for mechano-responsive optical material systems are created b... more ABSTRACT Rational design strategies for mechano-responsive optical material systems are created by introducing a simple experimental system that can continuously vary the state of bi-axial stress to induce various wrinkling patterns, including stripes, labyrinths, herringbones, and rarely observed checkerboards, that can dynamically tune the optical properties. In particular, a switching of two orthogonally oriented stripe wrinkle patterns from oxidized polydimethylsiloxane around the critical strain value is reported, as well as the coexistence of these wrinkles forming elusive checkerboard patterns, which are predicted only in previous simulations. These strain-induced wrinkle patterns give rise to dynamic changes in optical transmittance and diffraction patterns. A theoretical description of the observed pattern formation is presented which accounts for the residual stress in the membrane and allows for the fine-tuning of the window of switching of the orthogonal wrinkles. Applications of wrinkle-induced changes in optical properties are demonstrated, including a mechanically responsive instantaneous privacy screen and a transparent sheet that reversibly reveals a message or graphic and dynamically switches the transmittance when stretched and released.
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Proceedings of the National Academy of Sciences of the United States of America, Jan 4, 2014
Recently, diffraction elements that reverse the color sequence normally observed in planar diffra... more Recently, diffraction elements that reverse the color sequence normally observed in planar diffraction gratings have been found in the wing scales of the butterfly Pierella luna. Here, we describe the creation of an artificial photonic material mimicking this reverse color-order diffraction effect. The bioinspired system consists of ordered arrays of vertically oriented microdiffraction gratings. We present a detailed analysis and modeling of the coupling of diffraction resulting from individual structural components and demonstrate its strong dependence on the orientation of the individual miniature gratings. This photonic material could provide a basis for novel developments in biosensing, anticounterfeiting, and efficient light management in photovoltaic systems and light-emitting diodes.
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ABSTRACT Rational design strategies for mechano-responsive optical material systems are created b... more ABSTRACT Rational design strategies for mechano-responsive optical material systems are created by introducing a simple experimental system that can continuously vary the state of bi-axial stress to induce various wrinkling patterns, including stripes, labyrinths, herringbones, and rarely observed checkerboards, that can dynamically tune the optical properties. In particular, a switching of two orthogonally oriented stripe wrinkle patterns from oxidized polydimethylsiloxane around the critical strain value is reported, as well as the coexistence of these wrinkles forming elusive checkerboard patterns, which are predicted only in previous simulations. These strain-induced wrinkle patterns give rise to dynamic changes in optical transmittance and diffraction patterns. A theoretical description of the observed pattern formation is presented which accounts for the residual stress in the membrane and allows for the fine-tuning of the window of switching of the orthogonal wrinkles. Applications of wrinkle-induced changes in optical properties are demonstrated, including a mechanically responsive instantaneous privacy screen and a transparent sheet that reversibly reveals a message or graphic and dynamically switches the transmittance when stretched and released.
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We report on solution-processible high permittivity nanocomposite gate insulators based on BaTiO3... more We report on solution-processible high permittivity nanocomposite gate insulators based on BaTiO3 nanoparticles, surface-modified with a phosphonic acid, in poly(4-vinylphenol) for organic field-effect transistors. The use of surface-modified BaTiO3 nanoparticles affords high quality nanocomposite thin films at large nanoparticle volume fractions (up to 37 vol %) with a large capacitance density and a low leakage current (10-8 A/cm2). The fabricated pentacene field-effect transistors using these nanocomposites show a large on/off current ratio (Ion/off 104-106) due to the high capacitance density and small leakage current of the gate insulator.
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Conference on Lasers and Electro-Optics 2010, 2010
... Mikhail A. Kats1*, Darren J. Lipomi2, Philseok Kim1, Sung H. Kang1, Joanna Aizenberg1, George... more ... Mikhail A. Kats1*, Darren J. Lipomi2, Philseok Kim1, Sung H. Kang1, Joanna Aizenberg1, George M. Whitesides2, Federico Capasso1 1School of ... We acknowledge Christian Pflugl, RomainBlanchard, and Benjamin Wiley for helpful discussions, as well as support from the ...
Bookmarks Related papers MentionsView impact
Building and Environment, 2014
Bookmarks Related papers MentionsView impact
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Nanotechnology, Jan 10, 2014
The development of a stain-resistant and pressure-stable textile is desirable for consumer and in... more The development of a stain-resistant and pressure-stable textile is desirable for consumer and industrial applications alike, yet it remains a challenge that current technologies have been unable to fully address. Traditional superhydrophobic surfaces, inspired by the lotus plant, are characterized by two main components: hydrophobic chemical functionalization and surface roughness. While this approach produces water-resistant surfaces, these materials have critical weaknesses that hinder their practical utility, in particular as robust stain-free fabrics. For example, traditional superhydrophobic surfaces fail (i.e., become stained) when exposed to low-surface-tension liquids, under pressure when impacted by a high-velocity stream of water (e.g., rain), and when exposed to physical forces such as abrasion and twisting. We have recently introduced slippery lubricant-infused porous surfaces (SLIPS), a self-healing, pressure-tolerant and omniphobic surface, to address these issues. He...
Bookmarks Related papers MentionsView impact
Advanced Optical Materials, 2013
ABSTRACT Rational design strategies for mechano-responsive optical material systems are created b... more ABSTRACT Rational design strategies for mechano-responsive optical material systems are created by introducing a simple experimental system that can continuously vary the state of bi-axial stress to induce various wrinkling patterns, including stripes, labyrinths, herringbones, and rarely observed checkerboards, that can dynamically tune the optical properties. In particular, a switching of two orthogonally oriented stripe wrinkle patterns from oxidized polydimethylsiloxane around the critical strain value is reported, as well as the coexistence of these wrinkles forming elusive checkerboard patterns, which are predicted only in previous simulations. These strain-induced wrinkle patterns give rise to dynamic changes in optical transmittance and diffraction patterns. A theoretical description of the observed pattern formation is presented which accounts for the residual stress in the membrane and allows for the fine-tuning of the window of switching of the orthogonal wrinkles. Applications of wrinkle-induced changes in optical properties are demonstrated, including a mechanically responsive instantaneous privacy screen and a transparent sheet that reversibly reveals a message or graphic and dynamically switches the transmittance when stretched and released.
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Proceedings of the National Academy of Sciences of the United States of America, Jan 4, 2014
Recently, diffraction elements that reverse the color sequence normally observed in planar diffra... more Recently, diffraction elements that reverse the color sequence normally observed in planar diffraction gratings have been found in the wing scales of the butterfly Pierella luna. Here, we describe the creation of an artificial photonic material mimicking this reverse color-order diffraction effect. The bioinspired system consists of ordered arrays of vertically oriented microdiffraction gratings. We present a detailed analysis and modeling of the coupling of diffraction resulting from individual structural components and demonstrate its strong dependence on the orientation of the individual miniature gratings. This photonic material could provide a basis for novel developments in biosensing, anticounterfeiting, and efficient light management in photovoltaic systems and light-emitting diodes.
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ABSTRACT Rational design strategies for mechano-responsive optical material systems are created b... more ABSTRACT Rational design strategies for mechano-responsive optical material systems are created by introducing a simple experimental system that can continuously vary the state of bi-axial stress to induce various wrinkling patterns, including stripes, labyrinths, herringbones, and rarely observed checkerboards, that can dynamically tune the optical properties. In particular, a switching of two orthogonally oriented stripe wrinkle patterns from oxidized polydimethylsiloxane around the critical strain value is reported, as well as the coexistence of these wrinkles forming elusive checkerboard patterns, which are predicted only in previous simulations. These strain-induced wrinkle patterns give rise to dynamic changes in optical transmittance and diffraction patterns. A theoretical description of the observed pattern formation is presented which accounts for the residual stress in the membrane and allows for the fine-tuning of the window of switching of the orthogonal wrinkles. Applications of wrinkle-induced changes in optical properties are demonstrated, including a mechanically responsive instantaneous privacy screen and a transparent sheet that reversibly reveals a message or graphic and dynamically switches the transmittance when stretched and released.
Bookmarks Related papers MentionsView impact
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We report on solution-processible high permittivity nanocomposite gate insulators based on BaTiO3... more We report on solution-processible high permittivity nanocomposite gate insulators based on BaTiO3 nanoparticles, surface-modified with a phosphonic acid, in poly(4-vinylphenol) for organic field-effect transistors. The use of surface-modified BaTiO3 nanoparticles affords high quality nanocomposite thin films at large nanoparticle volume fractions (up to 37 vol %) with a large capacitance density and a low leakage current (10-8 A/cm2). The fabricated pentacene field-effect transistors using these nanocomposites show a large on/off current ratio (Ion/off 104-106) due to the high capacitance density and small leakage current of the gate insulator.
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