Channel integrated optoelectronic tweezer chip for microfluidic particle manipulation

作者：Christian Witte, Julien Reboud, Jonathan M. Cooper, Steven L. Neale · 发表于：Journal of Micromechanics and Microengineering · 年份：2020 · DOI：10.1088/1361-6439/ab6c72 · 被引用次数：16 · 研究领域：Microfluidic and Bio-sensing Technologies、Electrowetting and Microfluidic Technologies、Microfluidic and Capillary Electrophoresis Applications

Abstract Light patterned electrical fields have been widely used for the manipulation of microparticles, from cells to microscopic electronic components. In this work, we explore a novel electromechanical phenomenon for particle focusing and sorting where the electrical field patterns are shaped by a combination of the light patterned photoconductor and the channel geometry. This effect results from the combination of particle polarisation described by the Clausius–Mossotti relation and the engineering of large electric gradients produced by choosing the channels height to suit the size of the particles being manipulated. The matched geometry increases the distortion of the field created by a combination of the illuminated photoconductor and the particles themselves and hence the non-uniformity of the field they experience. We demonstrate a new channel integration strategy which allows the creation of precisely defined channel structures in the OET device. By defining channels in photoresist sandwiched between upper and lower ITO coated glass substrates we produce robust channels of well controlled height tailored to the particle. Uniquely, the top substrate is attached before photolithographically defining the channels. We demonstrate versatile control using this effect with dynamically reconfigurable light patterns allowing the retention against flow, focusing and sorting of micro particles within the channels. Contrary to traditional designs, this channel integrated device...