• Title, Summary, Keyword: self-assembly

Search Result 645, Processing Time 0.04 seconds

Low Cost, Large Area Nanopatterning via Directed Self-Assembly

  • Kim, Sang-Uk
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • /
    • pp.24-25
    • /
    • 2011
  • Molecular self-assembly has several advantages over other nanofabrication methods. Molecular building blocks ensure ultrafine pattern precision, parallel structure formation allows for mass production and a variety of three-dimensional structures are available for fabricating complex structures. Nevertheless, the molecular interaction for self-assembly generally relies on weak forces such as van der Waals force, hydrogen bonding, or hydrophobic interaction. Due to the weak interaction, the structure formation is usually slow and the degree of ordering is low in a self-assembled structure. To promote self-assembly, directed assembly methods employing prepatterned substrates or external fields have been developed and gathered a great deal of technological attention as a next generation nanofabrication process. In this presentation a variety of directed assembly methods for soft nanomaterials including block copolymers, peptides and carbon nanomaterials will be introduced. Block copolymers are representative self-assembling materials extensively utilized in nanofabrication. In contrast to colloid assembly or anodized metal oxides, various shapes of nanostructures, including lines or interconnected networks, can be generated with a precise tunability over their shape and size. Applying prepatterned substrates$^{1,2}$ or introducing thickness modulation$^3$ to block copolymer thin films allowed for the control over the orientational and positional orderings of self-assembled structures. The nanofabrication processes for metals, semiconductors$^4$, carbon nanotubes$^{5,6}$, and graphene$^{6,7}$ templating block copolymer self-assembly will be presented.

  • PDF

Three-Dimensional Self-Assembly of Gold Nanoparticles Using a Virus Scaffold

  • Kang, Aeyeon;Lee, Young-Mi;Kang, Hyo Jin;Chung, Sang Jeon;Yun, Wan Soo
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • /
    • pp.651-651
    • /
    • 2013
  • Templated strategy is a very powerful tool for creating multi-dimensional self assembly of nanomaterials. Since viral protein cages have a uniform size with a well-defined structure, they can serve as an excellent template for the formation of a three-dimensional self-assembly of synthetic nanoparticles. In this study, we have examined the feasibility of the 3D self-assembly of gold nanoparticles of various sizes using a brome mosaic virus (BMV) capsid with cysteine groups expressed on its surface as a scaffold for the assembly. It was found that the three-dimensional clusters of gold nanoparticles with a designed structure were attainable by this approach, which was verified by transmission electron microscope (TEM) and dynamic light scattering (DLS) analysis.

  • PDF

A self-learning rule-based assembly algorithm (자기학습 규칙베이스 조립알고리즘)

  • 박용길;조형석
    • 제어로봇시스템학회:학술대회논문집
    • /
    • /
    • pp.1072-1077
    • /
    • 1992
  • In ths paper a new active assembly algorithm for chamferless precision parts mating, is considered. The successful assembly task requires an extremely high position accuracy and a good knowledge of mating parts. However, conventional assembly mehtod alone makes it difficult to achieve satisfactory assembly performance because of the complexity and the uncertainties of the process and its environments such as imperfect knowledge of the parts being assembled as well as the limitation of the devices performing the assebled as well as the limitation of the devices performing the assembly. To cope with these problems, a self-learning rule-based assembly algorithm is proposed by intergaring fuzzy set theory and neural network. In this algortihm, fuzzy set theory copes with the complexity and the uncertainties of the assembly process, while neural network enhances the assembly schemen so as to learn fuzzy rules form experience and adapt to changes in environment of uncertainty and imprecision. The performance of the proposed assembly algorithm is evaluated through a series of experiments. The results show that the self-learning fuzzy assembly scheme can be effecitively applied to chamferless precision parts mating.

  • PDF

Electrochemical Properties of Viologen Self-Assembly Monolayer Using QCM (수정진동자를 이용한 Viologen Self-Assembly 단분자막의 전기화학적 특성)

  • 옥진영;신훈규;박재철;장정수;권영수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.6
    • /
    • pp.496-500
    • /
    • 2003
  • Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electrodes as well as micellar assemblies, which can be profitably utilized for display devices, photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator. Fromherz et al studied the self-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface[1]. The electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency(ΔF) and resonant resistance(R). The redox process of viologen was observed with resonant frequency(ΔF).

Self-Assembled Block Copolymers: Bulk to Thin Film

  • Kim, Jin-Kon;Lee, Jeong-In;Lee, Dong-Hyun
    • Macromolecular research
    • /
    • v.16 no.4
    • /
    • pp.267-292
    • /
    • 2008
  • Block copolymers that two or more polymer chains are covalently linked have drawn much attention due to self-assembly into nanometer-sized morphology such as lamellae, cylinders, spheres, and gyroids. In this article, we first summarize the phase behavior of block copolymers in bulk and thin films and some applications for new functional nanomaterials. Then, future perspectives on block copolymers are described.

A Decentralized Self-Control Strategy for Assembly Cell Using Bucket Brigade (Bucket Brigade를 기반으로 한 분산자율형 조립셀 운영전략)

  • Koo, Pyung Hoi
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.41 no.4
    • /
    • pp.330-337
    • /
    • 2015
  • A bucket-brigade is a way of transporting items where items are passed from one person to the next. The operation of the bucket brigade imitates the cooperative behavior of ants when brood, food or other resources are moved. Koo (2009) presented a bucket brigade-based assembly cell where each worker follows a simple rule: perform assembly operations on a product until the next worker downstream takes it over; then go back to the previous worker upstream to take over a new assembly job. In this way, the flow line is self-balanced without any predetermined job assignment. However, there are some productivity losses related to hand-off and blocking. This paper examines the hand-off and blocking losses and presents a new bucket brigade-based assembly cell where working areas for each assembler is restricted with the help of buffer interfaces. Simulation experiments are used to validate the performance of the new assembly system.

Supramolecular Nanomaterials Derived from Self-Assembly of Dendritic Building Blocks

  • Park, Chi-Young;Lee, Sang-Wha;Lim, Ji-No;Lim, Moon-Seob;Kim, Chul-Hee
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • /
    • pp.91-92
    • /
    • 2006
  • The fine-tuned dendrons provide unique supramolecular self-assemblies in various environments such as in water, organic media, and solid-liquid interfaces. They form nanotubes, vesicles, thin films, columns, lamellar nanoribbons depending on the condition of self-assembly process. Unique characteristics of self-assembly of the amide dendrons are described. In addition, elucidation of the structural correlation between the building blocks and the assemblies, stabilization of assembled structure, and transformation of supramolecular assemblies by using external stimuli. Particular emphasis is placed on the formation of cyclodextrin-covered organic nanotubes derived from self-assembly of amide dendrons and their supramolecular transformation. Finally, unique biosensory characteristics of the self-assembled nanotubes will be discussed.

  • PDF

Unprecedented Molecular Architectures by the Controlled Self-Assembly of ${\beta}$-Peptide Foldamer

  • Kwon, Sun-Bum;Lee, Hee-Seung
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • /
    • pp.204-204
    • /
    • 2011
  • During past decades, several types of peptide-based scaffolds, ranging from simple aromatic dipeptide to small protein fragments, have been studied to understand the underlying mechanism and mimic to create artificial nano/microstructures. However, a limited number of design principles have still been reported in peptidic scaffolds allowing well-defined self-assembled structure formation, presumably due to the intrinsic large conformational flexibility of natural peptides. In this presentation, we report the first example of highly homogeneous, well-defined and finite architectures by the ${\beta}$-peptide self-assembly.

  • PDF

Self-assembly of Dumbbell-shaped Rod Amphiphiles Based on Dodeca-p-phenylene

  • Huang, Zhegang;Liu, Libin;Lee, Eun-Ji;Lee, Myong-Soo
    • Bulletin of the Korean Chemical Society
    • /
    • v.29 no.8
    • /
    • pp.1485-1490
    • /
    • 2008
  • Dumbbell-shaped aromatic amphiphilic molecules consisting of a dodeca-p-phenylene as a rigid segment and oligoether dendrons as a flexible chains were synthesized, characterized, and their aggregation behavior was investigated in the bulk and at the air-water interface. In contrast to the molecule 2 which shows a nematic liquid crystalline state, molecule 1 based on shorter dendritic chains was observed to self-assemble into a 3-D primitive orthorhombic supercrystal. And molecule 1 at the air-water interface was observed to reorganize from circular plates to ring structures by lateral compressions.

Electrochemical Properties of Viologen Self-Assembly Monolayer Using QCM (수정진동자를 이용한 Viologen Self-Assembly 단분자막의 전기화학적 특성)

  • Ock, J.Y.;Song, S.H.;Shin, H.K.;Park, J.C.;Chang, J.S.;Chang, S.M.;Kwon, Y.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.403-406
    • /
    • 2002
  • Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electroeds as well as micellar assemblies. which can be profitably utilized for display devices. photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator[1-3]. Fromherz et al studied the se1f-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface[4]. In this study, the electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency$({\Delta}F)$ and resonant resistance(R). The redox process of viologen was observed with resonant frequency$({\Delta}F)$.

  • PDF