School of Engineering, Institute for Integrated Micro and Nano Systems, The University of Edinburgh, Edinburgh EH9 3JF, United Kingdom.
Biomicrofluidics. 2010 Jun 29;4(2):022811. doi: 10.1063/1.3456626.
A review is presented of the present status of the theory, the developed technology and the current applications of dielectrophoresis (DEP). Over the past 10 years around 2000 publications have addressed these three aspects, and current trends suggest that the theory and technology have matured sufficiently for most effort to now be directed towards applying DEP to unmet needs in such areas as biosensors, cell therapeutics, drug discovery, medical diagnostics, microfluidics, nanoassembly, and particle filtration. The dipole approximation to describe the DEP force acting on a particle subjected to a nonuniform electric field has evolved to include multipole contributions, the perturbing effects arising from interactions with other cells and boundary surfaces, and the influence of electrical double-layer polarizations that must be considered for nanoparticles. Theoretical modelling of the electric field gradients generated by different electrode designs has also reached an advanced state. Advances in the technology include the development of sophisticated electrode designs, along with the introduction of new materials (e.g., silicone polymers, dry film resist) and methods for fabricating the electrodes and microfluidics of DEP devices (photo and electron beam lithography, laser ablation, thin film techniques, CMOS technology). Around three-quarters of the 300 or so scientific publications now being published each year on DEP are directed towards practical applications, and this is matched with an increasing number of patent applications. A summary of the US patents granted since January 2005 is given, along with an outline of the small number of perceived industrial applications (e.g., mineral separation, micropolishing, manipulation and dispensing of fluid droplets, manipulation and assembly of micro components). The technology has also advanced sufficiently for DEP to be used as a tool to manipulate nanoparticles (e.g., carbon nanotubes, nano wires, gold and metal oxide nanoparticles) for the fabrication of devices and sensors. Most efforts are now being directed towards biomedical applications, such as the spatial manipulation and selective separationenrichment of target cells or bacteria, high-throughput molecular screening, biosensors, immunoassays, and the artificial engineering of three-dimensional cell constructs. DEP is able to manipulate and sort cells without the need for biochemical labels or other bioengineered tags, and without contact to any surfaces. This opens up potentially important applications of DEP as a tool to address an unmet need in stem cell research and therapy.
本文综述了电泳力（DEP）的理论、技术发展和当前应用的现状。在过去的 10 年中，大约有 2000 篇出版物涉及到这三个方面，目前的趋势表明，该理论和技术已经足够成熟，大多数努力现在都指向在生物传感器、细胞治疗、药物发现、医学诊断、微流控、纳米组装和颗粒过滤等领域应用 DEP 来满足未满足的需求。用于描述在非均匀电场中作用于粒子的 DEP 力的偶极子近似已经发展到包括多极贡献，以及与其他细胞和边界表面相互作用引起的微扰效应，以及对于纳米粒子必须考虑的电双层极化的影响。不同电极设计产生的电场梯度的理论建模也达到了先进水平。技术的进步包括复杂电极设计的发展，以及新材料（例如硅聚合物、干膜电阻器）的引入，以及用于制造 DEP 器件的电极和微流控的新方法（光刻、电子束光刻、激光烧蚀、薄膜技术、CMOS 技术）。现在每年大约有 300 篇左右的科学出版物发表关于 DEP 的研究，其中大约四分之三都指向实际应用，与之相匹配的是越来越多的专利申请。本文给出了自 2005 年 1 月以来授予的美国专利摘要，并概述了为数不多的已感知工业应用（例如，矿物分离、微抛光、流体液滴的操纵和分配、微组件的操纵和组装）。DEP 技术也已经发展到足够成熟的程度，可以用于操纵纳米粒子（例如，碳纳米管、纳米线、金和金属氧化物纳米粒子）来制造器件和传感器。现在大多数努力都集中在生物医学应用上，例如目标细胞或细菌的空间操纵和选择性分离富集、高通量分子筛选、生物传感器、免疫测定以及三维细胞构建的人工工程。DEP 能够在不需要生化标记或其他生物工程标记的情况下，也无需与任何表面接触，对细胞进行操纵和分类。这为 DEP 作为一种工具来解决干细胞研究和治疗中的未满足需求提供了潜在的重要应用。
