Manipulation of Self-Assembled Microparticle Chains by Electroosmotic Flow Assisted Electrorotation in an Optoelectronic Device

Abstract

A method incorporating the optically induced electrorotation (OER) and alternating current electroosmotic (ACEO) effects, for the formation and motion control of microparticle chains, is numerically and experimentally demonstrated. In this method, both the rotating electric field and ACEO fluid roll are generated around the border between light and dark area of the fluidic chamber in an optoelectronic tweezers (OET) device. The experimental results show that the particle chains can self-rotate in their pitch axes under the rotating electric field produced due to the different impedances of the photoconductive layer in light and dark areas, and have a peak self-rotating rate at around 1 MHz. The orbital movement of entire particle chain around the center of ACEO fluid roll can be achieved from 0.5 to 600 kHz. The strength of OER motion and ACEO-caused orbital movement of particle chains can be adjusted by changing the frequency of alternating current (AC) voltage. This non-contact method has the potential for spatially regulating the posture, orientation and position of microparticle chains.

Optoelectronic tweezers: a versatile toolbox for nano-/micro-manipulation

“…For example, many cells exhibit unique self-rotation behaviors in OET systems, which can be used as a label-free biomarker to rapidly identify and characterize cells of different kinds. [180][181][182] Although the mechanism responsible for self-rotation of cells in OET still remains debatable, [181][182][183][184][185][186][187][188] it is demonstrated that the rotation is determined by the electric field (i.e., frequency and field intensity) and polarization properties of cells. Fig.…”

Microscopic Particle Manipulation via Optoelectronic Devices

“…The detailed information could be found in Ref. [49]. The microparticle chain can be self-assembled under an e-field E, and then, a polarization could be induced in the particle chain.…”

Design and optimization of an octuple-electrode array for micro-particle chain rotation via electrorotation integrated with machine vision technology

“…[28][29][30] Additionally, these methods can be combined for enhanced effectiveness. 31 Mischel et al introduced a sinusoidal excitation voltage with a 90°phase difference across four electrodes, which could generate a uniform rotating electric field for electrokinetic rotation. 32 Moreover, Huang et al proposed a novel ROT technique for three-dimensional electrokinetic rotation of particles, achieving 3D rotation with the control of direction and speed.…”

“…Zhu et al combined optical-induced electric rotation (OER) with alternating current electroosmosis (ACEO) to control the rotational motion of particle chains through numerical simulations and experiments. 34 In order to achieve vertical rotation and rolling phenomena of particle chains, Zhao et al introduced a newly developed volumetric polarization and integration (VPI) method to study the movement of pearl chains under DEP in a flow condition. 35 Furthermore, Cheng et al achieved the electric rotation of particle polymers through parallel plate electrodes and inter-particle forces.…”