Microfabrication technologies in dielectrophoresis applications--a review.

DEP is an established technique for particle manipulation. Although first demonstrated in the 1950s, it was not until the development of miniaturization techniques in the 1990s that DEP became a popular research field. The 1990s saw an explosion of DEP publications using microfabricated metal electrode arrays to sort a wide variety of cells. The concurrent development of microfluidics enabled devices for flow management and better understanding of the interaction between hydrodynamic and electrokinetic forces. Starting in the 2000s, alternative techniques have arisen to overcome common problems in metal-electrode DEP, such as electrode fouling, and to increase the throughput of the system. Insulator-based DEP and light-induced DEP are the most significant examples. Most recently, new 3D techniques such as carbon-electrode DEP, contactless DEP, and the use of doped PDMS have further simplified the fabrication process. The constant desire of the community to develop practical solutions has led to devices which are more user friendly, less expensive, and are capable of higher throughput. The state-of-the-art of fabricating DEP devices is critically reviewed in this work. The focus is on how different fabrication techniques can boost the development of practical DEP devices to be used in different settings such as clinical cell sorting and infection diagnosis, industrial food safety, and enrichment of particle populations for drug development.