Development of 3D Printing Electrode Design for high Skin Adhesion in Smart Wear

( Heeran Lee ),( Soyoung Kim ),( Yejin Lee ),( Okkyung Lee ) 한국감성과학회 2021 한국감성과학회 국제학술대회(ICES) Vol.2021 No.-

The aim of this study was to develop a 3D printed electrode shape that can be applied to smarwear for high body adhesion. To improve adhesiveness, 5 pattern types (plain, striped, checked, circular, radial cut-out) of electrodes was developed to, modeled in thickness of 1 mm and 0.5 mm. Their adhesiveness to body by shapes and thickness were analyzed by image processing the contact area. As a result showed that radial cut-out shape was the best when arm part had horizontal radius curvature of 3.36 cm and when thickness of electrode was 1.0 mm. Stripe and check shapes were the best when thickness of electrode was 0.5 mm. On the other hands, check shape had the best adhesiveness when thigh part had horizontal radius of curvature of 4.96 cm and when thickness of electrode was 1.0 mm. All shapes of electrodes were excellent when thickness was 0.5 mm. The adhesiveness by shape of electrode depended on radius of curvature of body or thickness of electrode.

A Study of Heat Transfer depending on 3D Printing Material and Shape for Protector Development

( Heeran Lee ),( Soyoung Kim ),( Yejin Lee ),( Okkyung Lee ) 한국감성과학회 2021 한국감성과학회 국제학술대회(ICES) Vol.2021 No.-

The purpose of this study was to obtain basic data on thermal comfort in clothing by measuring the amount of surface temperature change depending on the 3D printing material and shape in order to investigate the heat transfer characteristics. The sample materials were 100 % EVA(Ethylene-vinyl acetate) foam, 100 % thermoplastic polyurethane (TPU), and thermoplastic polyurethane/Ethylene-vinyl acetate foam blend. In addition, each sample was printed with and without 7 mm square holes. As a result, the amount of surface temperature change was different depending on the material. The samples 3D printed with 100 % TPU performed better heat transfer than samples from 100% EVA foam. Also, it was found that the temperature transfer was better for the sample with holes, while the temperature transfer was slower when the sample was covered with a fabric.

A Study of Heat Transfer depending on 3D Printing Material and Shape for Protector Development

( Heeran Lee ),( Soyoung Kim ),( Yejin Lee ),( Okkyung Lee ) 한국감성과학회 2021 추계학술대회 Vol.2021 No.0

The purpose of this study was to obtain basic data on thermal comfort in clothing by measuring the amount of surface temperature change depending on the 3D printing material and shape in order to investigate the heat transfer characteristics. The sample materials were 100 % EVA(Ethylene-vinyl acetate) foam, 100 % thermoplastic polyurethane (TPU), and thermoplastic polyurethane/Ethylene-vinyl acetate foam blend. In addition, each sample was printed with and without 7 mm square holes. As a result, the amount of surface temperature change was different depending on the material. The samples 3D printed with 100 % TPU performed better heat transfer than samples from 100% EVA foam. Also, it was found that the temperature transfer was better for the sample with holes, while the temperature transfer was slower when the sample was covered with a fabric.

Development of 3D Printing Electrode Design for high Skin Adhesion in Smart Wear

( Heeran Lee ),( Soyoung Kim ),( Yejin Lee ),( Okkyung Lee ) 한국감성과학회 2021 추계학술대회 Vol.2021 No.0

The aim of this study was to develop a 3D printed electrode shape that can be applied to smarwear for high body adhesion. To improve adhesiveness, 5 pattern types (plain, striped, checked, circular, radial cut-out) of electrodes was developed to, modeled in thickness of 1 mm and 0.5 mm. Their adhesiveness to body by shapes and thickness were analyzed by image processing the contact area. As a result showed that radial cut-out shape was the best when arm part had horizontal radius curvature of 3.36 cm and when thickness of electrode was 1.0 mm. Stripe and check shapes were the best when thickness of electrode was 0.5 mm. On the other hands, check shape had the best adhesiveness when thigh part had horizontal radius of curvature of 4.96 cm and when thickness of electrode was 1.0 mm. All shapes of electrodes were excellent when thickness was 0.5 mm. The adhesiveness by shape of electrode depended on radius of curvature of body or thickness of electrode.

Comparison of absorption based on the location of seam of cloth diaper

( Heeran Lee ),( Hyojeong Lee ),( Yejin Lee ) 한국패션비즈니스학회 2016 패션 비즈니스 Vol.20 No.6

A necessity for infants, diapers are not only used over long durations, but are also in direct contact to the infants` skin, making the choice of diaper to be of utmost importance. Current interest in cloth diapers is rapidly increasing because of issues concerning the baby`s health, green environment, and economy. However, previous researches on cloth diapers are limited to simply investigating the form and material of commercial cloth diapers. There are few in-depth researches for the optimal cloth diaper development. This is therefore a fundamental research for the development of optimized cloth diapers, and analyzes the difference in absorption depending on the placement of seam line (liner, darts, and I pattern), the locations of liquid spraying (1 cm and 8 cm ahead of the center), and the amount of liquid capacity (10 and 20 ml). Currently, the development of diaper patterns considers the crotch shape of the infants and the skin length deformation. As a result, in the case of the I-pattern, the horizontal seam line prevents water from spreading to the front and back, thus reducing the absorbed area. This result was more clearly visible when water was sprayed at the center. The effect of the seam line became more obvious when there was more water (20 ml); also, when water was sprayed at the center, more leakage was observed. Using the results of this research, implementation of horizontal seam is expected to prevent the upward spread of urine.

Mn-ferrite 의 중금속 흡착특성 - 폐 페라이트의 중금속폐수 처리 활용 가능성

이상훈(Sanghoon Lee),윤창주(Changjoo Yoon),이희란(Heeran Lee) 대한자원환경지질학회 2003 자원환경지질 Vol.36 No.5

본 연구는 폐산화철을 이용한 폐수 중금속 제거 가능성을 알아보고자 시도되었다. 실제 폐수와폐산화철을 적용하 기에 앞서 상업적으로 구입가능한 Mn-ferrite 를 이용하여 실내 회분식 시험을 통한 흡착실험을 실시하여 pH, 접촉시 간, 중금속 농도 및 온도 등과 같은 다양한 흡착 조절인자들을 이용하여 페라이트에 의한 Cd 과 Pb 의 흡착 및 제거특 성을 알아보았다. 접촉시간을 1 에서 360 분까지 변화하여 흡착속도를 측정하였으며 일정온도에서 Cd 와 Pb 의 농도를 변화시켜 흡착등온선을 구하였다. 또한 온도(15~35 o C) 와 pH(4~10) 변화에 따른 흡착특성 변화를 고찰하였다. Cd 과 Pb 는 Freundlich 식에 잘 맞았으며 Cd 에 비하여 Pb 가 더 흡착이 잘 되었다. pH 가 높을수록 Cd 와 Pb 가 더 잘 흡착 되었으며 이는 pH 증가에 따라 수소이온 농도가 감소하고 결과적으로 표면의 흡착가용 장소가 증가하기 때문인 것으로 생각된다. 같은 pH 에서 원소의 농도가 증가할 때 흡착이 더 잘 일어났다. 온도 역시 Pb 와 Cd 의 흡착능에 영향을 미쳤으며 Pb 의 경우 온도가 증가할수록 흡착정도가 높아지는 반면 Cd 의 경우 덜 흡착이 되었다. Cd 는 Pb 에 비하여더 온도에 영향을 받으며 이러한 Cd 와 Pb 의 흡착특성 차이는 Cd 에 비하여 Pb 가 더 hard 한 특성 때문인 것으로 생각된다. 본 연구는 폐산화철을 이용하여 각종 폐수 중금속을 제거하는 공정에 사용될 수 있음을 시사한다. We investigated possible application of waste ferrite in treating Cd and Pb in wastewater. Adsorption of Cd and Pb on Mn-Ferrite are influenced by several controlling factors such as contact time, heavy metal concentrations, pH and temperature . Both Cd and Pb achieved adsorption equilibrium within 5 minutes. Based upon this kinetic data, 24 hours of contact time was allowed for other experiment. The adsoprtion of Cd and Pb was high at high pH and high ion concentrations. The reaction was also affected by temperature. Adsorption isotherms fits well with the Freundlich isotherm equation. pH is the main controlling fator in Cd, Pb adsoption on the Mn-ferrite. Cd showed S type adsorption curve while Pb showed sorption edges, depending on the Pb concentrations.

Optimization Method for Developing 2D Patterns of 3D Character Dolls

( Heeran Lee ) 한국감성과학회 2017 한국감성과학회 국제학술대회(ICES) Vol.2017 No.-

Because characters are easily accessible to consumers, they are recognized as positive products that can Because characters are easily accessible to consumers, they are recognized as positive products that can stimulate the economy as well as publicity. Therefore, new characters are being developed not only in industry but also in public institutions, and they are commercialized as doll products. To commercialize a doll, a 2D pattern of characters is needed. However, since the shape and size of characters vary, it is possible to obtain a 2D pattern through several pattern corrections and sample operations. However, in many cases, developed 2D patterns are not reused. Therefore, in this study, we suggested the optimal method to develop 3D model data into 2D patterns so that 2D patterns can be developed with minimum time and one sample operation. For this purpose, 2D cover patterns were developed from two 3D models which are different in sizes and shapes. The variables of this study were determined in three steps (small, medium, large) depending on the triangle area. And we measured the area and shape change rate, and development time of 2D pattern developed by variables. As a result, the most common method was to use the triangular piece area as a medium step. In addition, when the curved surface is flat, it is suitable to divide it into a large step having a large triangular piece area. However, it was found that the best method is to use a small step with a small complex triangular area such as the head or leg of the model.

Usage and satisfaction of bed cloth fabrics: a reality study

( Heeran Lee ) 한국패션비즈니스학회 2016 패션 비즈니스 Vol.20 No.6

Presently, sleep disorders are rapidly increasing due to sudden social development and lifestyle diversification. Among the various factors contributing to comfortable sleep, bedclothes are a major factor that readily influence the sleeping conditions, as they directly come in contact with the human body. This study therefore researches use and purchasing status of bedclothes by consumers, as well as the subjective satisfaction. This would accordingly help us to understand the consumers` performance needs, and collect basic data to develop bedclothes that assist comfortable sleep. This study used multiple choice questions and a 5-point Likert scale in a survey-style research. The results of the study indicate that consumers prudently considered practicality and durability, as bedclothes are seldom purchased. The most preferred material was cotton, but the use of microfiber, a new material, has also increased. Further, consumers` preferred lightweight bedclothes that displayed excellent water absorption, thermal insulation, durability, detergency, and flexibility. Hence, bedclothes developed according to the results of this study are expected to aid comfortable sleep.

Methods and Locations for Embedding Heating Units into Base Layers for Smart Wear: Analyzing Thermal Responses to Automatic Heat Regulation

Heeran Lee,Okkyung Lee,Soyoung Kim 한국섬유공학회 2022 Fibers and polymers Vol.23 No.5

To set the on-off mode for efficient automatic heat regulation of a smart base layer, this study determined whetherthe location of the temperature input sensors for automatic heat regulation and the temperature range set for on-off wasadequate in a particular environment-clothing-body system. The experimental environment was set to both neutral (23.0±1.0 ºC,20±5 % RH) and cold (5±0.5 ºC, 45±5 % RH, wind velocity: 0.2 m/s). With eight male subjects wearing T-shirts andouterwear over smart base layers, both their skin temperatures and the clothing microclimate temperatures were measuredwhen the heating unit was in operation. Wearability was thus assessed, thereby allowing an examination of the relationshipbetween the temperature values of the input sensor and those of the heating unit. In this context, we set the reference value ofthe fabric-covered sensor to 34 °C and sewed the operating portion of the heat-generating pad into the inner side of the backarea of the base layer. When the heating unit temperature was set to 34 °C, the clothing microclimate temperature changed inresponse to changes in the external environmental temperature; this was detected by the temperature sensor attached to theheating unit of the smart base layer. Thus, in both environments, the back area skin temperature was maintained almostconsistently within the upper limit (38.4±2.0 ºC) of the skin temperature comfort zone. As a result of examining thetemperature changes according to the layering structure of clothing where the heat-generating device was attached, thelocation where temperature sensor A was embedded to receive the input signal within the heating unit and the set pointreflected the effects of the environmental temperature, body temperature, and clothing in balance, thereby demonstrating itssuitability for automatic heat regulation input signals. Here, the overall thermal sensation was 1.3-2.0 points and thussomewhat warm; overall comfort was also higher than average, at 6.4-7.3 points. In sum, neither the overall thermal sensationor comfort level substantially changed when moving to low-temperature indoor environments after wearing the automaticheat-regulating smart base layer. We therefore established that the body comfort zone was adequately maintained in bothgiven environments when the operating portion of the device was embedded into the base layer of the three-layer clothingsystem and while the reference value of the sensor temperature was set.

3D Pattern Development of Ergonomic Outdoor Pants Based on Skin Deformation in Trekking Postures

Heeran Lee,Yejin Lee,Kyunghi Hong 대한인간공학회 2013 대한인간공학회 학술대회논문집 Vol.2013 No.10

Objective: The purpose of this study is to suggest design lines and patterns of 3D outdoor pants which is comfortable during movements. Background: Outdoor brands often use streamlined design lines to design high performance outdoor wear. Because slim-fit has larger contact area with the skin, sewing seams along the design line can cause discomfort or even restrict body movement when walking, climbing, or sitting for hours. To reduce such discomfort, we need to find the appropriate location for cutting lines that do not interfere with body movement when using diagonal sewing line for the streamline design. Also, 3D pattern development of ergonomic outdoor pants was developed. Method: We observed three-dimensional U-shape of the crotch and developed the 2D pants pattern of the optimal crotch curve which is closer to V-shape compared to the conventional pattern. To design ergonomic outdoor pants, we selected the design line where the changes in skin length were the least while moving based on the skin deformation mapping. And the inseam of upper part was removed to adjust the fabric to the pendulum movement of the thigh. In addition, stress distribution along the front crotch curve was investigated to facilitate the hip joint movement while maintaining appearance. Results: 3D outdoor pants without inseam was rated more comfortable (p=0.024<SUP>*</SUP>) around the crotch compared to the 3D pattern with inseam. Appearance of the front of the pants was improved when 80 % of the stress was distributed near the point of error source. Conclusion: The sewing lines passing through the zone of least change is comfortable and 3D pants without inseam was rated more comfortable in trekking postures. Application: The skin deformation mapping for design lines and 3D arrangement methods can be applied to other functional clothing development.