We created artificial cilia and demonstrated that such cilia successfully pump fluid in a microfluidic device. The cilia were assembled from micron-sized superparamagnetic beads and pre-manufactured trenches in a photoresist layer were used to assist the beads to form long chains. The beads were held together by an external magnetic field that was also used to drive the cilia in a periodic but nonreciprocal manner. We observed generated fluid flow above the ciliated surface, measured the fluid flow velocity and determined the velocity profile as a function of beating parameters.
COBISS.SI-ID: 23251239
We used superparamagnetic particles to create artificial cilia and assembled and actuated them with an external magnetic field. Additional fluorescent tracer particles were introduced into the system that enabled observation and detection of velocity and direction of the flow. We studied the influence of cilium beating parameters on the flow patterns and observed that the motion is composed of three components: two rotational and one translational motion that contributes to net pumping of the fluid.
COBISS.SI-ID: 24932135
We numerically determined the optimal beating patterns of cilia according to their energetic efficiency. We showed that maximizing the efficiency of a single cilium leads to curly, often symmetric, and somewhat counter-intuitive patterns. When looking at a densely ciliated surface, the optimal patterns become remarkably similar to what is observed in microorganisms like Paramecium. We demonstrated that metachronal coordination is essential for efficient pumping and the highest efficiency is achieved with antiplectic waves.
COBISS.SI-ID: 25073447
By assembling superparamagnetic microspheres we created an artificial membrane. The main feature of such a membrane are its self-healing properties: if torn, the attractive interactions between the membrane building blocks result in 'healing' of the membrane. By using the magic angle precession of the external magnetic field, we obtained isotropic pair attraction similar to the van der Waals force between atoms. Many-body polarization interactions lead to formation of chains, networks and finally stable membranes.
COBISS.SI-ID: 2204516