• Title/Summary/Keyword: Polymer lens

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Development of Hyaluronic Acid-Functionalized Hydrogel Lens and Characterization of Physical Properties and Lysozyme Adsorption (Hyaluronic acid의 첨가방법에 따른 하이드로겔 콘택트렌즈의 물리적 특성과 lysozyme 흡착량 비교)

  • Lim, Hwa-lim;Kim, Ho-joong;Jun, Jin
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.3
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    • pp.285-291
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    • 2015
  • Purpose: The hydrogel lenses have been functionalized with HA(Hyaluronic Acid) using two different methods: construction of an IPN(Interpenetrating Polymer Networks) and formation of CCB(Chemical Covalent Bonding). The lysozyme adsorption and physical properties such as optical transmittance and water content of the hydrogel lenses have been investigated in order to determine whether method is suitable for the application potentials in contact lens industry. Methods: HA have been added to the hydrogel lenses prepared in the Lab using the two different method, e.g. IPN and CCB. The optical transmittance was measured in the wavelength range of 300~800 nm. The water content was measured by the gravimetric method using 0.9% NaCl saline solution. The amounts of adsorbed lysozyme on the contact lenses was analyzed by HPLC after incubation for 12h in artificial tears. Results: The water content of the HA added hydrogel contact lenses was increased, and the lens made by IPN method showed higher water content than the lens made by CCB method. The optical transmittance was over 90% both before and after addition of HA. Comparing the lysozyme adsorption reduction ratio, contact lens manufactured by IPN method was 60.0%, and the lens made by CCB method was 40.4%. Conclusions: CCB method is appropriate to distribute the functional material evenly throughout the lens, whereas IPN method is effective for the case of giving the functionality on the lens surface without phase separation.

Optimum Design and Characterization of F-Theta Lens by a 3D Printer(I) (초점보정 렌즈설계 및 3D 프린터 이용 가공 특성평가(I))

  • Shin, Hyun-Myung;Yoon, Sung-Chul;Choi, Hae-Woon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.4
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    • pp.43-48
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    • 2015
  • A focal length-correcting lens called the F-theta lens is required to compensate for the different focus on spot size due to the deflected incident laser beam. The F-theta lens was designed by the ray tracing method and fabricated by a 3D printer with polymer-based material. The designed F-theta lens is able to compensate for the focus on spot size by an incidence angle of 0 to 2 degrees. Based on the analysis of the simulation, there was almost no aberration in the $0^{\circ}C$ incidence angle, and the maximum of $50{\mu}m$ of aberration was observed at the incidence angle of $2^{\circ}$. Diffraction-encircled energy was analyzed to characterize the designed optics, and an image simulation was performed to confirm the actual image resolution.

Microlens fabricated by laser irradiation (레이저를 이용한 마이크로렌즈 제조에 관한 연구)

  • 윤경구;이성국;김재구;김철새;김재도
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.748-751
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    • 2000
  • Microlens made by laser radiation method have advantages in the easiness of their fabrication. The process is based on the projection of a chromium-on-quartz reticle on to the Polymer using a pulsed 248nm KrF excimer laser. Fabrication process is a fluence-dependent rate and density. The lens shape is defined by a rotationally symmetric sluence distribution with smooth radial variation in the image plane of the reticle. A typical lens of 50㎛ diameter was fabricated by irradiating 2000 laser pulses within 40 seconds. The experimental results show microlens fabrication by UV laser is possible and well worth studying further.

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Biosafety of the New Soft Contact Lens Materials in the Fibroblast L-929 Cell Line (흰쥐의 섬유아세포 L-929를 이용한 새로운 Soft Contact Lens 소재의 생물안전성 검증)

  • You, Young-Hyun;Nam, Joo-Hyeung;Kim, Bieong-Kil;Kim, Soon-Bok;Moon, Ik-Jae;Kim, Jong-Pil;Seu, Young-Bae
    • Microbiology and Biotechnology Letters
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    • v.37 no.1
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    • pp.75-79
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    • 2009
  • In this study, we polymerized new materials for soft contact lens using HEMA (2-hydroxyethyl methacrylate) which is the based-monomer of soft contact lens, EGDMA (ethylene glycol dimethacrylate) as cross linkage agent, and the new additives of monoester or di-ester derived from itaconic acid commercially produced by the fermentation of Asp. itaconicus. New polymer materials for soft contact lens were synthesized with the mixture of HEMA and mono- or diester at different ratios and presented to a good water content and oxygen transmissibility (Dk/L) values. In case of polymerization with HEMA and mono-ester (15%), the water content and oxygen transmissibility of contact lens were found to be good values at 57.6% and 28.5 Dk respectively. The mixture of HEMA and mono-ester is more excellent than HEMA/di-ester in the water content and oxygen transmissibility. The toxicity of new contact lens materials were confirmed in the fibroblast L-929 cell line using a agar overlay test and a growth inhibition test with the extract solution of contact lens.

A Study on the Signal Analysis of Corona Discharge on the Polymer Insulator using UV Sensor Array (UV 센서 어레이를 이용한 폴리머 애자의 코로나 방전 신호분석 연구)

  • Choi, Myeong-Il;Kim, Jae-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.4
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    • pp.16-20
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    • 2014
  • To prevent any accident in electric power utilities, many researches for inspection and diagnosis deteriorations occurring by corona discharges have been continuously studying. Inspection and diagnosis of electric power utility is very important to prevent an accident. This paper studies a measurement of ultra-violet(UV) ray of corona discharges on polymer insulators using an UV sensor array with an optic lens. The detection of an UV signal begins at 60kV, which is about 37.5% of the breakdown voltage of the polymer insulator and the stronger the high voltage increased to the polymer insulator was. It can be determined that the polymer insulator mounted on a live part must be examined when the discharge risk exceeds approximately 40%. In conclusion, the status of power utilities can be checked using an UV sensor.

Synthesis of Polymer Materials Containing Platinum Nanoparticles and Their Application for Contact Lenses (백금 나노입자를 포함한 고분자재료의 합성 및 콘택트렌즈로의 응용)

  • Ye, Ki-Hun;Sung, A-Young
    • Journal of the Korean Chemical Society
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    • v.54 no.1
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    • pp.99-104
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    • 2010
  • Platinum nanoparticles were added to a mixture of HEMA (2-hydroxyethyl methacrylate), NVP (N-vinyl pyrrolidone) and MMA (methyl methacrylate) in a mould at various concentrations. The resulting mixture was copolymerized by heating at $70^{\circ}C$ for 40 min, $80^{\circ}C$ for 40 min, and $100^{\circ}C$ for 40 min, respectively. The physical properties of contact lens were then measured. The oxygen transmissibility of $9{\sim}15{\times}10^{-9}$ cm/s mL $O_2$/mL ${\times}$ mmHg, water content of 34.22~35.52%, refractive index of 1.432~1.435, visible transmittance of 88.3~91.2% and tensile strength of 0.141~0.152 kgf were obtained. The addition of platinum nanoparticles to the polymer allowed the contact lens to have various colors without artificial coloring agents. The polymer materials satisfied the physical properties required to produce contact lenses, making the material suitable to be applied as a functional material for ophthalmological purposes.

Improving the Sensitivity of an Ultraviolet Optical Sensor Based on a Fiber Bragg Grating by Coating With a Photoresponsive Material (광반응 재료가 코팅된 단주기 광섬유격자 기반 자외선센서의 광민감도 향상 연구)

  • Kim, Woo Young;Kim, Chan-Young;Kim, Hyun-Kyoung;Ahn, Tae-Jung
    • Korean Journal of Optics and Photonics
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    • v.26 no.2
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    • pp.83-87
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    • 2015
  • This study was focused on developing an optical sensor that monitors ultraviolet (UV) light. Recently, we proposed and demonstrated a novel, highly sensitive UV sensor based on a fiber Bragg grating (FBG). To ensure that the incident UV light is focused on the FBG surface, the sensor was coated with an azobenzene polymer material that acts as a UV-induced stretchable functional material, in combination with a cylindrical focal lens. In this study we have improved the sensitivity of the sensor by employing a cylindrical focal mirror as a curved reflector, to refocus the UV light passing through the FBG. We considered the performance of several different types of reflectors and chose the optimal radius of curvature for the reflector. Compared to the UV sensor without an auxiliary device, the sensitivity of the FBG sensor with a focal lens and a curved reflector was 15 times as high.

Development of Surface-mount-type Crown-shaped Lens for Reducing Glare Effect of Light-emitting Diode Light Source (LED 광원의 눈부심 현상을 감소시키기 위한 표면 실장형 CR 렌즈 개발)

  • Park, Yong Min;Bang, Hyun Chul;Seo, Young Ho;Kim, Byeong Hee
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.1
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    • pp.64-68
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    • 2014
  • This paper introduces the use of a crown-shaped (CR) lens to effectively diffuse the light from a light-emitting diode (LED) without any loss in the light intensity, in contrast to polymer-bulb-type diffusers. The diffusion lens was designed based on the Snell's law, which describes the physical path of a ray passing through the boundary between different media. CR lenses were fabricated by polydimethylsiloxane (PDMS) casting and UV-embossing processes, which used a pre-designed metal mold and UV-curable resin, respectively. Through experiments and optical evaluations, it was verified that the newly proposed CR lens not only decreased the vertical light strength and glare effect from an LED light source but also improved the diffusion characteristics while maintaining the quality of the LED's light intensity.

A Study on Water Droplet Lens Effect of UV Laser Micromachining Process (UV 레이저 미세 가공공정에서의 물 액적 렌즈 효과에 관한 연구)

  • Shin, Bo-Sung;Lee, Jung-Han
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.5
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    • pp.773-777
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    • 2012
  • Recently UV laser micromachining processes is widely introduced to meet the needs of advanced components of IT, BT and ET industries. Due to the characteristics of non-contact and high-speed laser processing, UV laser micromachining is applied to manufacture very thin substrate such as polymer, metals and composite. These minimum line width obtained by UV laser micromachining is generally determined from laser wavelength, optical lens and its numerical aperture. In this paper we will show the lens effect of water droplet on the surface of workpiece to reduce the line width when UV laser light is irradiated and focused through the water droplet. Because of the refraction effect generated by the semi-spherical or spherical shape of water droplet, we can find smaller line width. And water droplet could not only protect thermal deformation, but also carry away burr around micro dent. Firstly fundamental theory of minimum line width was derived from relationship between the geometry of water droplet and laser light trace, and then experimental and simulation results will be finally compared to verify the effectiveness of water droplet lens effect of UV laser micromachining process.

Development of New Soft Contact Lens Materials Using Ester-Monomers of Itaconic Acid from Aspergillus itaconicus (Aspergillus itaconicus 유래 itaconic acid의 ester-monomer를 이용한 새로운 soft contact lens 소재 개발)

  • You, Young-Hyun;Nam, Joo-Hyeung;Kim, Bieong-Kil;Kim, Soon-Bok;Moon, Ik-Jae;Kim, Jong-Pil;Seu, Young-Bae
    • Journal of Life Science
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    • v.19 no.4
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    • pp.538-542
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    • 2009
  • In this study, we confirmed water content and oxygen permeability of new polymeric materials synthesized from itaconic acid used for soft contact lenses. In this study, we polymerized materials for soft contact lenses using HEMA (2-hydroxyethyl methacrylate), the based-monomer of soft contact lenses, EGDMA (ethylene glycol dimethacrylate) as a cross linkage agent, and the new additives mono-ester or di-ester derived from itaconic acid commercially produced by the fermentation of A. itaconicus. New polymer materials for contact lenses were synthesized with the mixture of HEMA and mono- or di-ester at different ratios and water content and oxygen permeability (Dk) was analyzed. In polymerizing HEMA and mono-ester (15%), the water content and oxygen permeability of contact lenses were found to be of good value at 57.7% and 28.6 Dk respectively. The mixture of HEMA and mono-ester is more excellent than HEMA/di-ester in regards to water content and oxygen permeability. The water content and oxygen permeability of soft contact lenses made by new polymeric materials were highly represented.