マイクロチャネルの内部で,表面に導かれた液体の流れが流れます
1The Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Science (New York, N.Y.)
|February 13, 2001
まとめ
研究者らは,表面エネルギーを使って液体の流れを制御するためにマイクロチャネルをパターン化しました. この技術は,水性液体を水性経路に限定し,圧力に敏感なスイッチと,大規模なガス液体インターフェイスを必要とするアプリケーションを可能にします.
科学分野:
- 表面化学について
- マイクロフリウジック
- マテリアルサイエンス 材料科学
背景:
- 表面の自由エネルギーのパターンを設定することは,マイクロチャネルにおける液体の振る舞いを制御するために重要です.
- 液体収束のための既存の方法は,しばしば複雑なチャネル幾何学を必要とします.
研究 の 目的:
- マイクロチャネルネットワーク内での液体フローの精密な制御のための方法を開発し,パターン化された表面自由エネルギーを使用します.
- 圧力感知スイッチとガス液体反応アプリケーションの作成を実証する.
主な方法:
- 表面の自由エネルギーをパターン化するために,自己組み立ての単層化学を用いた.
- マルチストリーム・ラミナー・フローとフォトリトグラフィーを採用し,パターニングを行いました.
- 水性液体をパターン化されたマイクロチャネルに導入し,圧力を介して制御された流れを行います.
主要な成果:
- 水性液体は,臨界圧力値を下回る水友性の経路に成功裏に閉じ込められました.
- 閉じ込めるための最大圧力は,液体の表面の自由エネルギー,接触角度,チャネル深さによって決定されました.
- 圧力に敏感なスイッチを作成するための表面向け液体の流れが実証されています.
結論:
- パターン化された表面自由エネルギーは,マイクロチャネルにおける液体の流れを制御するための堅固な方法を提供します.
- この技術は,圧力感受性スイッチを含む新しい微流体装置の開発を可能にします.
- このアプローチは,ガス-液体反応など,大規模なガス-液体インターフェースを必要とするアプリケーションに有効です.
関連する概念動画
01:18Rise of Liquid in a Capillary Tube
When very thin cylindrical tubes, called capillaries, are dipped in a liquid, the liquid rises or falls in the tube compared to the surrounding liquid. This phenomenon is called capillary action. Capillary action occurs due to the combination of two opposing forces: the cohesive forces of the liquid, which cause it to stick to itself and form a rounded shape, and the adhesive forces between the liquid and the walls of the container, which cause the liquid to be attracted to the container walls.
01:28Capillary Exchange
The cardiovascular system's chief role is to disseminate gases, nutrients, waste, and other substances to the body's cells. Small molecules like gases, lipids, and lipid-soluble substances directly diffuse through capillary wall endothelial cell membranes. Glucose, amino acids, and ions, including sodium, potassium, calcium, and chloride, use transporters for facilitated diffusion via membrane-specific channels. Glucose, ions, and bigger molecules may also pass through intercellular clefts.
01:27Steady Flow of a Fluid Stream
Consider a control volume, such as a pipe with solid boundaries, through which fluid flows and changes direction due to the impulse exerted by the resulting force from the pipe walls. In steady flow, the mass of fluid entering the control volume at a given time, t, with velocity v1, is equal to the mass leaving after infinitesimal time dt, with velocity v2.
During this process, the momentum of the fluid within the control volume remains constant over the time interval dt. By applying the...
During this process, the momentum of the fluid within the control volume remains constant over the time interval dt. By applying the...
01:22Surface Tension of Fluid
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies with...
Surface tension varies with...
01:19Capillarity in Fluid
Capillarity describes the movement of liquid in small spaces without external forces acting on it. The capillarity is driven by surface tension and adhesive interactions between the liquid and surrounding solid surfaces. This effect is often seen in narrow tubes, porous materials, and fine particles.
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...
01:28Continuity Equation
The continuity equation asserts that the mass flow rate must remain constant for a steady flow of an incompressible fluid within a confined system. This principle applies to systems where fluid passes through varying cross-sectional areas, such as nozzles, syringes, and pipes.
The mass flow rate is expressed as:
The mass flow rate is expressed as: