相关实验视频
Updated: Jul 15, 2025
08:23
Finite Element Modelling of a Cellular Electric Microenvironment
Published on: May 18, 2021
3.5K
在充电频率周围的空间不均的交流电场中的pH梯度;对两个不同的几何和电极被动化的研究
Azade Tahmasebi1, Sanaz Habibi2, Jeana L Collins1
1Department of Chemical Engineering, Michigan Technological University, Houghton, MI 49931, USA.
Micromachines
|September 28, 2023
概括
这项研究研究了微流体器件中的pH梯度,使用介电泳 (DEP). 结果显示,法拉戴反应影响pH值,变化在更高频率下降,并且在星形电极设计中更为显著.
科学领域:
- 电动运动学 电动运动学
- 微流体学 微流体学
- 生物物理学的生物物理.
背景情况:
- 介电泳 (DEP) 对于微流体设备中的细胞和生物分子检测至关重要.
- 由于离子梯度,设备性能随着时间的推移而降低,影响可重现性和精度.
- 了解这些离子梯度是提高诊断微设备准确性的关键.
研究的目的:
- 描述微流体器件中的pH梯度,与电极充电频率相对应的不同频率.
- 为了研究电极几何学 (T形与星形) 对pH梯度的影响.
- 评估氧化物 (HfO2) 薄膜在减轻法拉代反应中的作用及其对pH的影响.
主要方法:
- 在微流体室中使用T形和星形微电极生成非线性交流电场.
- 量化pH值在不同频率 (0.2-1.4倍充电频率) 的空间和时间上有所变化.
- 使用电场模拟和测试HfO2薄膜来分析表面反应和离子电迁移.
主要成果:
- 识别了发生在电极充电频率,电极充电频率以上和以下的法拉代反应.
- 观察到由于法拉代反应的pH值变化与频率成反比例,在星形几何形状中更为明显.
- 证明HfO2膜表现出频率依赖的行为,有效地抑制法拉代反应.
结论:
- 法拉戴克反应对DEP微器件中的pH梯度有显著的贡献.
- 频率和电极几何是影响pH稳定的关键因素.
- 通过减少法拉代干扰,HfO2涂层在提高微流体诊断设备的稳定性和可靠性方面表现有前途.
相关概念视频
01:23Electric Field of a Charged Disk
2.2K
The simplest case of a surface charge distribution is the uniformly charged disk. Calculating its electric field also helps us calculate the electric field of a large plane of charge.
The system's symmetry is in the cylindrical directions across the plane of the charge. As a result, the electric fields created by various surface charge elements nullify each other in the direction parallel to the surface. Thereby, the resulting electric field is perpendicular to the plane. Since the disk is...
The system's symmetry is in the cylindrical directions across the plane of the charge. As a result, the electric fields created by various surface charge elements nullify each other in the direction parallel to the surface. Thereby, the resulting electric field is perpendicular to the plane. Since the disk is...
2.2K
01:16Electric Field of Parallel Conducting Plates
1.0K
Gauss' law relates the electric flux through a closed surface to the net charge enclosed by that surface. Gauss's law can be applied to find the electric field and the charge enclosed in a region depending on its charge distribution.
Consider a cross-section of a thin, infinite conducting plate having a positive charge. For such a large thin plate, as the thickness of the plate tends to zero, the positive charges lie on the plate's two large faces. Without an external electric...
Consider a cross-section of a thin, infinite conducting plate having a positive charge. For such a large thin plate, as the thickness of the plate tends to zero, the positive charges lie on the plate's two large faces. Without an external electric...
1.0K
01:26What is an Electrochemical Gradient?
110.5K
Adenosine triphosphate, or ATP, is considered the primary energy source in cells. However, energy can also be stored in the electrochemical gradient of an ion across the plasma membrane, which is determined by two factors: its chemical and electrical gradients.
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...
110.5K
01:16Electrostatic Boundary Conditions
506
Consider an external electric field propagating through a homogeneous medium. When the electric field crosses the surface boundary of the medium, it undergoes a discontinuity. The electric field can be resolved into normal and tangential components. The amount by which the field changes at any boundary is given by the difference between the field components above and below the surface boundary.
The surface integral of an electric field is given by Gauss's law in integral form and is related to...
The surface integral of an electric field is given by Gauss's law in integral form and is related to...
506
01:22Electric Field of a Non Uniformly Charged Sphere
1.6K
Gauss's law states that the electric flux through any closed surface equals the net charge enclosed within the surface. This law is beneficial for determining the expressions for the electric field for a particular charge distribution if the electric flux is known.
Consider a non-uniformly charged sphere, for which the density of charge depends only on the distance from a point in space and not on the direction. Such a sphere has a spherically symmetrical charge distribution. Here, the electric...
Consider a non-uniformly charged sphere, for which the density of charge depends only on the distance from a point in space and not on the direction. Such a sphere has a spherically symmetrical charge distribution. Here, the electric...
1.6K
01:12Determining Electric Field From Electric Potential
4.5K
The electric field and electric potential are related to each other. If the electric field at various points in the region of interest is known, it can be used to calculate the electric potential difference between any two points. Similarly, if the electric potential is known for various points, then it is possible to calculate the electric field.
In general, regardless of whether the electric field is uniform, it points in the direction of decreasing potential because the force on a positive...
In general, regardless of whether the electric field is uniform, it points in the direction of decreasing potential because the force on a positive...
4.5K