Injection molding of a nanostructured plate and measurement of its surface properties

Yoo, Yeong-Eun; Kim, T.H.; Choi, Doo-Sun; Hyun, Seungmin; Lee, H.J.; Lee, K.H.; Kim, S.K.; Kim, B.H.; Seo, Youngkyun; Lee, H.G.; Lee, J.S.

doi:10.1016/j.cap.2008.12.023

Cited by 36 publications

(22 citation statements)

References 8 publications

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“…The AAO layer, however, cannot be used several times in the polymer molding processes with both a high pressure and a large temperature variation due to its weakness and brittleness 27–28. Several groups, including ours, realized durable nickel nano–stamps containing various types of nanostructure could be fabricated by combining the electroforming and anodization processes 29–30. This cost–effective method of nanofabricating nickel nano–stamps can be regarded as promising for realizing mass–replication of polymer nano–featured substrates through the polymer molding process.…”

Section: Discussionmentioning

confidence: 99%

Mass‐producible Nano‐featured Polystyrene Surfaces for Regulating the Differentiation of Human Adipose‐derived Stem Cells

Park¹,

Je²,

Han³

et al. 2012

Macromolecular Bioscience

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In this study, we report an efficient and cost-effective method of fabricating polystyrene (PS) nano-featured substrates containing nanopore (NPo) and nanopillar (NPi) arrays based on hot embossing using nickel nano-stamps. We investigate the behavior of adipose-derived stem cells (ASCs), including adhesion, morphology, proliferation and differentiation, on the replicated PS surfaces. Compared to a flat substrate, NPo- and NPi-featured substrates do not alter the morphology of stem cells. However, both NPo- and NPi-featured substrates induce different integrin expression and lower formation of focal adhesion complexes. In addition, ASCs on the NPo-featured substrate exhibit greater adipogenic differentiation, while the NPi-featured substrate induces higher osteogenic differentiation.

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Section: Discussionmentioning

confidence: 99%

Mass‐producible Nano‐featured Polystyrene Surfaces for Regulating the Differentiation of Human Adipose‐derived Stem Cells

Park¹,

Je²,

Han³

et al. 2012

Macromolecular Bioscience

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“…A further increasing sub-area is the influence on surface properties by the use of micro-structures (Yoo et al 2009). Some examples from nature are the self-cleaning surface of the lotus blossom (Nosonovsky and Bhushan 2008;Kim et al 2008;Lee et al 2007; Lee et al 2006), the nonreflecting cornea of moths' eyes, tribological and hydrodynamic performance of scales on beaked salmon and shark skins.…”

Section: Introductionmentioning

confidence: 99%

Study on the replication quality of micro-structures in the injection molding process with dynamical tool tempering systems

et al. 2010

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The injection molding of micro-structures is a promising mass-production method for a broad range of materials. However, the replication quality of these structures depends significantly on the heat flow during the filling stage. In this paper, the filling and heat transfer of v-groove and random structures below 5 lm is investigated with the help of an AFM (atomic force microscope) and thermo couples. A numerical model is developed to predict the filling of surface structures during the filling and packing stage. The model implies the use of simple fully developed flow models taking the power-law material model into account. This permits investigation into which ways several processing parameters affect the polymer flow in the surface structures. The mold wall temperature, which has significant effects on the polymer flow, is varied by using a variothermal mold temperature control system to validate the model proposed.

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“…Since the formation of a viscous or solidified layer hinders replication, it is widely recognized that replication is improved by raising melt injection temperature or cavity (insert) surface temperature . Raising these temperatures while keeping other parameters fixed will, however, reduce filling pressure.…”

Section: Replication Of Micro‐features In Injection Moldingmentioning

confidence: 99%

Replication of surface micro‐features using variothermal injection molding: Application to micro‐fluidics

Pittman¹,

Wlodarski²

2017

Polymer Engineering & Sci

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We study injection molding of mesoscale items with µm‐scale surface features, namely micro‐fluidic channels, relating replication quality to process conditions. Using variothermal molding, the variables are the pre‐heat temperature of the cavity insert surface before melt injection and the mold cooling start time. Surface temperatures and in‐cavity melt pressures are continuously measured. Rounded upper corners of the micro‐channels are used as an index of replication quality. For polymethylmethacrylate the thickness of a layer with solid‐like properties (below 124°C) is calculated and used with pressures to interpret results. It is shown how improved replication correlates with low layer thickness at the end of the compression phase when pressures are at a maximum, and the necessity of properly timed cooling to lock in replication before melt pressures fall. Results show how the inter‐relationship of layer thickness and melt pressure is controlled by pre‐heat temperature and cooling switch‐on time. Delayed cooling can result in poorer replication, due to a retraction effect of the plastic. Too early cooling also reduces replication of parallel‐to‐flow features downstream of transverse features, and of the replication of transverse features on their downstream side. Good replication of 100 and 70 µm channels requires lower pre‐heat than 400 µm ones. POLYM. ENG. SCI., 58:1726–1738, 2018. © 2017 Society of Plastics Engineers

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Injection molding of a nanostructured plate and measurement of its surface properties

Cited by 36 publications

References 8 publications

Mass‐producible Nano‐featured Polystyrene Surfaces for Regulating the Differentiation of Human Adipose‐derived Stem Cells

Mass‐producible Nano‐featured Polystyrene Surfaces for Regulating the Differentiation of Human Adipose‐derived Stem Cells

Study on the replication quality of micro-structures in the injection molding process with dynamical tool tempering systems

Replication of surface micro‐features using variothermal injection molding: Application to micro‐fluidics

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