• 대한기계학회논문집A
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• 제28권12호
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• pp.1871-1876
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• 2004

We demonstrate a novel fabrication technology for the microneedle array that can be used in the medical test field, which is transdermal drug delivery and blood analyte sampling. Previous researchers have used silicon-processed micromachining, a reactive ion etching, and molding techniques for the fabrication of microneedle array. However, these fabrication techniques have somewhat limitations apply to the microneedle array fabrication according to its application. Inclined LIGA process is suggested to overcome these problems. This process provides easier, sharper and longer out-of-plane microneedle array structure than conventional silicon-processed fabrication method did. Additionally, because of the advantage of the LIGA process based on mold fabrication for mass production, the polymer, PMMA(PolyMethylMethAcrylate), based microneedle array is useful as the mold base of nickel electroplating process; on the other hand, silicon-processed microneedle array is used in itself. In this research, we fabricate different types of out-of-plane microneedle array, which have different shape of tip, base and hole structure, using the inclined LIGA process. The fabricated microneedles have proper mechanical strength, height and sharpness to puncture human hand epidermis or dermis with less pain and without needle tip break during penetrating the skin.

• Journal of mucopolysaccharidosis and rare diseases
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• 제1권1호
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• pp.5-14
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• 2015

This paper addresses the state of arts of microneedles for the transdermal drug delivery applications. Microneedles can be classified based on materials and shapes. For the materials, microneedles could be made of ceramics, metals and polymers. The shape of the microneedles can be classified into solid and hollow microneedles. Methods of transdermal drug delivery based on microneedle patch are discussed, and various fabrication methods of microneedle patches are introduced.

• 대한의용생체공학회:의공학회지
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• 제39권1호
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• pp.30-35
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• 2018

Conventional drug delivery methods mainly include subcutaneous injection and oral administration. Subcutaneous injection has the advantages of delivering the correct concentration, but it might cause pain and trauma to patients. Although oral administrations do not accompany pain as the subcutaneous injection, unexpected side effects may occur because they undergo digestion process and it is not easy for many drugs to be exposed to targeted sites with proper concentration. While dissolving microneedles have been extensively studied to overcome the limitations of conventional subcutaneous injection, the effects on microneedle shapes for drug release have not been fully explored. In this study, the characteristics of hyaluronic acid microneedles for cone and quadrangular pyramidal shapes were examined by the size, volume, contact surface area, skin permeability, and dissolution rate. As a result, the cone shapes of hyaluronic acid microneedles had high skin permeability, and the quadrangular pyramid of shapes hyaluronic acid microneedles showed a fast dissolution rate, given by the large contact area on the skin. Based on the results, we could confirm that the shape of a dissolving microneedles can affect skin permeability and the drug delivery rate.

• Korean Chemical Engineering Research
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• 제59권3호
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• pp.429-434
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• 2021

약물의 피부 투과성을 향상시키기 위해 고안된 방법 중 하나인 용해성 마이크로니들의 재료로서 레시틴의 적용 가능성을 평가하고, 레시틴의 조성이 마이크로니들의 기계적 강도와 용해성, 그리고 최종적으로 rhodamine B (RhB)의 피부 투과성에 미치는 영향을 조사하였다. 마이크로니들용 몰드를 제작하는 기존의 포토리소그래피 방법에 비해서 간단하고 효율적인 laser-writing 기법을 이용하여 제작한 몰드로 균일한 모양과 크기의 바늘을 가진 용해성 마이크로니들을 제작하였다. 마이크로니들 내 레시틴의 조성은 바늘의 기계적 강도와 용해성에 영향을 미쳤으며, 그 결과 바늘 내 레시틴의 조성이 증가함에 따라서 바늘의 기계적 강도가 증가하고 최종적으로 마이크로니들에 탑재된 RhB의 피부 투과성이 향상되었다. 레시틴 대신 동일한 조성의 amylopectin (AP)가 함유된 마이크로니들과 비교하여 보면, 레시틴이 포함된 마이크로니들의 RhB 피부 투과성이 더 높은 것을 볼 수 있었다. 이러한 결과들은 레시틴이 용해성 마이크로니들의 재료로 사용될 수 있으며, 그 조성을 변화함에 따라서 마이크로니들의 피부에 대한 약물의 투과성을 제어할 수 있는 가능성이 있음을 보여준다.

• Design & Manufacturing
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• 제10권3호
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• pp.25-29
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• 2016

Recently, a hyaluronic acid micro needle patch for therapeutic and cosmetic purposes has been used by attaching directly to the skin with a pattern having a micro needle shape of 1/3 thickness of hair. These products are attracting attention as an innovative product that maximizes the effect by activating the active ingredient in the skin in the deep skin without blocking the horny layer because the micro needle shape exists on the patch surface so that it can penetrate effectively to the skin. Currently, DAB (droplet air blowing) or MEMS technology is used to make pattern shapes for patches. Because of this technology, manufacturing time is long and manufacturing cost is high, so we tried to develop the mold technology to machine the microneedle shape directly to the metal. In this study, we first fabricated a needle pattern with a quadrangular pyramid shape and finally produced a conical needle pattern.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.608-613
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• 2007

Fine pitch microprobe arrays are microneedle-like probes for inspecting the pixel of LCD panel. They are usually made of multilayers of metallic, nonmetallic, or combination of the two. In this study, the microprobe arrays were fabricated using the process applied for MEMS fabrication technology and they consist of BeCu, BeNi, or Si. Their contacting probing force and deflection were measured using the laser equipment. The design requirement are 5gf of a minimum contact force and $150{\mu}m$ of a maximum deflection. A lot of microprobe shape are possible satisfying the requirement. A double cantilever-type microprobe having needles on both ends were applied for this study. Several candidate were chosen using the topology and shape optimization technique subjected to the design requirements. Finite element results and experimental results were compared and both gave good correlation.

• 대한기계학회논문집A
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• 제40권8호
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• pp.731-736
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• 2016

본 연구에서는 의용생체공학에 널리 사용되는 미소바늘과 같은 3차원 고종횡비 미소구조물을 용이하게 제작할 수 있는 하이브리드 자외선 노광법에 대해 기술한다. 하이브리드 자외선 노광법은 기존에 사용되고 있는 경사노광, 회전노광 및 역노광을 혼합한 방법으로, 경사 및 회전노광은 경사진 축대칭 형상을 가지는 3차원 미소구조물의 제작이 가능하도록 하고 역노광은 자외선 노광공정 중 필연적으로 발생하는 하부기판에서의 자외선 반사를 최소화 시킨다. 자체 개발한 자외선 노광시스템과 SU-8 음성감광제를 이용하여 하이브리드 자외선 노광법의 다양한 공정조건이 최종 제작된 3차원 고종횡비 미소구조물 형상(종횡비, 선단의 곡률반경 등)에 미치는 효과를 확인한다. 또한 SU-8의 소프트 베이킹(soft baking) 조건과 미소구조물 선단 형상 사이의 관계에 대해서도 논의한다.