Microscale flow propulsion through bioinspired and magnetically actuated artificial cilia

Abstract

Recent advances in microscale flow propulsion through bioinspired artificial cilia provide a promising alternative for lab-on-a-chip applications. However, the ability of actuating artificial cilia to achieve a time-dependent local flow control with high accuracy together with the elegance of full integration into the biocompatible microfluidic platforms remains remote. Driven by this motive, the current work has constructed a series of artificial cilia inside a microchannel to facilitate the timedependent flow propulsion through artificial cilia actuation with high-speed (>40 Hz) circular beating behavior. The generated flow was quantified using micro-particle image velocimetry and particle tracking with instantaneous net flow velocity of up to 10 1 lm/s. Induced flow patterns caused by the tilted conical motion of artificial cilia constitutes efficient fluid propulsion at microscale. This flow phenomenon was further measured and illustrated by examining the induced flow behavior across the depth of the microchannel to provide a global view of the underlying flow propulsion mechanism. The presented analytic paradigms and substantial flow evidence present novel insights into the area of flow manipulation at microscale. V C 2015 AIP Publishing LLC. [http://dx

Pneumatically-actuated artificial cilia array for biomimetic fluid propulsion

“…These mechanisms complement the method of Chen et al 23 , that inducing flow reversal by changing the rotational direction of magnetically actuated cilia. However, two mechanisms are introduced to change flow direction: changing frequency or changing duty cycle above the bandwidth of the actuator.…”

An Integrated Artificial Cilia Based Microfluidic Device for Micropumping and Micromixing Applications

“…An observation zone with an area of 500 × 100 µm 2 , located at a distance of 270 µm from the terminal artificial cilia, was selected ( Figure 5 a). To achieve superior micropropulsion, the magnitude of the artificial cilia rotating frequencies were pre-meditated to 40 Hz; the details of the beating trajectory and its working mechanism can be found elsewhere [ 15 , 29 ]. The flow test zone was selected away from the artificial cilia array based on the hypothesis that flows in this zone are stable and free from any kind of oscillation induced by the continuous beating of the artificial cilia array.…”

“…A modulated pulse-width modulation (PWM) signal was implemented through a switching circuit to control the time duration and the amplitude of power supply. It should be noted that the proposed actuation system can generate a magnetic field up to 0.2 T. A detailed description of the actuation system can be found elsewhere [ 29 ].…”

Actuation of Liquid Flow by Guided Acoustic Waves on Punched Steel Tapes with Protruding Loops

“…Inspired by these attractive features numerous attempts to construct and to operate artificial cilia have been undertaken and various mechanisms for their actuation were introduced [16][17][18] . Among them were solutions operating by oscillating external electric fields [19][20][21] or magnetic fields acting on incorporated magnetic nanoparticles [22][23][24][25][26][27][28][29][30][31][32][33][34][35] , by optical [36] or pneumatic [37] internal deformation of the ciliate body or by shaking the base-layer substrate [38][39][40][41][42][43] . Many of these attempts were focused on the reconstruction of the naturally occurring asymmetric bending trajectories of individual cilia by using flexible materials such as electroactive polymers or polymer nanorods containing iron oxide nanoparticles [44] .…”