3.2. ICEK micromixers
Rapid and homogeneous mixing of different solutions in microfluidics is
vital for numerous LOC applications, such as biochemical reactions
(S.-J. Kim, Wang, Burns, & Kurabayashi, 2009), drug delivery (X. Jia et
al., 2016), biological agent detection (Cho, Chung, Kim, Jung, & Seo,
2015), and DNA hybridization (R. H. Liu, Lenigk, & Grodzinski, 2003).
Diffusion is the primary mechanism of fluid mixing in microscale due to
the low convective mass transfer (M. K. D. Manshadi et al., 2019).
Various types of passive and active micromixers have been developed to
increase the contact surface area (interface) and reduce the mixing
path, therefore enhancing the mixing in microchannels (Lee, Chang, Wang,
& Fu, 2011; Lee, Wang, Liu, & Fu, 2016). Electrokinetic micromixers
have demonstrated to be one of the most effective mixing methods in
microfluidics where their performance is dependent on mixing time,
length, and index (Lee et al., 2011; Rashidi, Bafekr, Valipour, &
Esfahani, 2018). ICEK electrokinetic-based micromixers, in specific,
have shown their potential for active mixing in microchannels due to
their high flexibility, controllability, and easy usage (Harnett,
Templeton, Dunphy-Guzman, Senousy, & Kanouff, 2008; Rashidi et al.,
2018). The generated MVs around polarizable surfaces (electrodes or
objects) increase chaotic movement in the electrolyte and therefore
induce notable mixing. Similar to ICEK micropumps, two primary
categories of ACEO and ICEO have shown high performance for microfluidic
applications and are discussed below.