• Elastomers and Composites
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• 제44권3호
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• pp.244-251
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• 2009

최근 들어, 자연의 기능성 표면을 모사하여 공학적으로 이용하려는 연구가 전세계적으로 급격히 증가하고 있다. 자연계에 존재하는 표면의 여러 기능을 우리 생활에 응용할 수 있다면, 현재 인류가 직면하고 있는 환경오염, 에너지고갈, 물/식량 부족 등의 문제들을 해결하는데 큰 도움이 될 뿐만 아니라, 우리가 일상생활에 사용하는 많은 제품들의 표면 기능을 고도화시킬 수 있기 때문이다. 이 글에서는 다양한 기능을 가진 자연의 표면 중 마이크로/나노구조물을 이용하여 초발수 특성을 갖는 표면에 대하여 살펴보고 초발수 표면의 이론적인 배경 및 초발수 표면을 구현하기 위한 여러 연구들에 대하여 소개하고자 한다.

• 한국정밀공학회지
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• 제29권1호
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• pp.19-24
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• 2012

We demonstrate the desert beetle back mimicking hybrid superhydrophilic/superhydrophobic patterned surface by using the combination method of colloidal lithography and gravure offset printing for nano and micro patterning, respectively. The two methods are cost-effective and industrially available techniques compared to the other nano/micro patterning methods. To verify the water collecting function of the hybrid surface, the water condensation behavior is investigated on the chilled surface in ambient temperature and high humidity. Due to the synergetic effect of drop and film wise condensation, the hybrid superhydrophobic/superhydrophilic surface shows the higher efficiency than one of single wettability surfaces. The work is underway to get the good patterns of hybrid surfaces for water collecting from the dew or fog.

• 대한기계학회논문집 C: 기술과 교육
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• 제1권2호
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• pp.211-219
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• 2013

기후가 무덥고 습해지면서 제습기의 사용이 증가하고 있지만, 제습기의 에너지 소비가 크고, 전기제품의 사용 증가로 인하여 전력이 부족하기에 제습기의 사용이 보편화되지 못 하고 있다. 제습기술은 오랜 시간 동안 최적화된 기술로써 기존기술을 바탕으로 에너지 효율을 높이는 데에는 한계에 도달했다고 볼 수 있다. 하지만, 높은 에너지 효율, 즉 소비전력이 낮으면서 제습성능이 높은 제습기의 개발 요구가 계속되고 있고, 그 해답은 자연모사기술에서 찾을 수 있다. 이 논문에서는 상용품인 제습기의 소비전력을 분석하고 자연에서 무동력으로 공기 중의 수분을 포집하는 딱정벌레 등껍질이나 식물들로부터 영감을 얻어 에너지 효율을 증가시킬 수 있는 아이디어를 살펴보고자 한다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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• pp.61-62
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• 2012

한국기계연구원에서 진행되고 있는 자연의 기능성 표면에 대한 연구를 소개한다. 특히 연잎의 자기세정효과와 나방눈의 반사방지 효과를 함께 가지는 다기능성 유리표면의 제작공정과 성능을 소개하고 향후 전망에 대하여 논한다.

• KSTLE International Journal
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• 제9권1_2호
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• pp.13-16
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• 2008

Surface Engineering is a field closely related to Tribology. Surfaces are engineered to reduce adhesion, friction and wear between moving components in engineering applications. On the contrary, it is also necessary to have high adhesion between surfaces so as to hold/stick surfaces together. In this context, surface engineering plays an important role. In recent times, scientists are drawing inspiration from nature to create effective artificial adhesive surfaces. This article provides some examples of novel surface engineering approaches conducted by various research groups worldwide that have significantly contributed in the creation of bio-inspired artificial adhesive surfaces.

• 센서학회지
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• 제32권1호
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• pp.31-38
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• 2023

Three-dimensional (3D) micro/nanostructures based on soft elastomers have received extensive attention in recent years, owing to their potential and advanced applicability. Designing and fabricating 3D micro/nanostructures are crucial for applications in diverse engineering fields, such as sensors, harvesting devices, functional surfaces, and adhesive patches. However, because of their structural complexity, fabricating soft-elastomer-based 3D micro/nanostructures with a low cost and simple process remains a challenge. Bio-inspired designs that mimic natural structures, or replicate their micro/nanostructure surfaces, have greatly benefited in terms of low-cost fabrication, scalability, and easy control of geometrical parameters. This review highlights recent advances in 3D micro/nanostructures inspired by nature for diverse potential and advanced applications, including flexible pressure sensors, energy-harvesting devices based on triboelectricity, superhydrophobic/-philic surfaces, and dry/wet adhesive patches.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.202-202
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• 2011

The research of 3-dimensional (3-D) scaffold for tissue engineering has been widely investigated as the importance of the 3-D scaffold increased. 3-D scaffold is needed to support for cells to proliferate and maintain their biological functions. Furthermore, its architecture defines the shape of the new bone and cartilage growth. Polycaprolactone (PCL) has been one of the most promising materials for fabricating 3-D scaffold owing to its excellent mechanical property and biocompatibility. However, there are practical problems for using it, in vitro and in vivo; extracellular matrix components and nutrients cannot penetrate into the inner space of scaffold, due to its hydrophobic property, and thus cell seeding and attachment onto the inner surface remain as a challenge. Thus, the surface modification strategy of 3-D PCL scaffold is prerequisite for successful tissue engineering. Herein, we utilized a mussel-inspired approach for surface modification of 3-D PCL scaffold. Modification of 3-D PCL scaffolds was carried out by simple immersion of scaffolds into the dopamine solution and stimulated body fluid, and as a result, hydroxyapatite-immobilized 3-D PCL scaffolds were obtained. After surface modification, the wettability of 3-D PCL scaffold was considerably changed, and infiltration of the pre-osteoblastic cells into the 3-D scaffold followed by the attachment onto the surface was successfully achieved.

• Tribology and Lubricants
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• 제33권6호
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• pp.256-262
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• 2017

Molten zinc plating is a process in which zinc is thinly coated over a metallic or non-metallic surface. It is used in various industrial fields for corrosion resistance and decoration. During the process, a steel sheet is passed through a roll that rotates inside the molten zinc liquid in the temperature range of $460^{\circ}C$ to $680^{\circ}C$, and the plating liquid flows into the roll causing abrasion and erosion of the roll surface. This problem is known to accelerate the replacement cycle of the roll and cause considerable economic loss owing to production line stoppage. Here, we propose a mechanism that operates at high temperature and pressure with a labyrinth type seal design to resolve this problem. We theoretically investigate the flow of the plating solution inside the seal and compute the minimum rotation speed required to prevent the plating solution from entering the seal chamber. In addition, we calculate the thermal deformation of the seal during operation and display thermally deformed dimensions at high temperatures. To verify the theoretical results, we perform experiments using pilot test equipment working in the actual plating environment. The experimental results are in good agreement with theoretical results. We expect our results to contribute towards the extension of the roll's life span and thereby reduce the economic losses.

• Current Optics and Photonics
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• 제7권1호
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• pp.97-103
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• 2023

In this paper, we propose Babinet-principle-inspired metasurfaces for strong resonant enhancement of local magnetic fields. The metasurfaces are designed as complementary structures of original metasurfaces supporting the local enhancement of electric fields. We show numerically that the complementary structures can support spoof magnetic surface plasmons that induce strong local magnetic fields without sacrificing the deep sub-wavelength-thick nature of the metasurface. By introducing a periodic array of metallic rods in the proximity of the metasurfaces, we demonstrate that a resonant enhancement of the local magnetic fields, more than 80 times the amplitude of an incident magnetic field, can emerge from a resonance of the spoof magnetic surface plasmons.

• 센서학회지
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• 제21권3호
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• pp.186-191
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• 2012

In this paper, we present a pH measurement method that uses a microcantilever-array-based biosensor system. It is composed of microcantilever array, liquid cell, micro syringe pump, laser diode array, position sensitive detector, data acquisition device, and data processing software. Four microcantilevers are functionalized with pH-sensitive MHA(mercaptohexadecanoic acid) as a probe, while three microcantilevers are functionalized with HDT(hexadecane thiol) as reference. We prepare PBS(phosphate buffered saline) solutions of different pH and inject them into the liquid cell with a predefined volumetric speed at regular time intervals. The functionalized mircocantilevers in the liquid cell deflect as a self-assembled monolayer on the microcantilever binds with probe molecules in the solution. The difference in deflection between the MHA-covered probe microcantilever and the HDT-covered reference microcantilever was used to compensate for thermal drift. The deflection difference clearly increases with increasing pH in the solution. It was shown that when the pH values of the PBS solutions are high, there were large variations in the deflection of microcantilevers, whereas there were small variations for low pH value. The experimental results show that the microcantilever array functionalized with MHA and HDT can detect pH value with good repeatability.