Authors: P.J. Glazer, J. Leuven, H. An, S.G. Lemay, E. Mendes
Affilation: Delft University of Technology, Netherlands
Pages: 138 - 141
Keywords: cilia, gels, smart materials, microactuators, hydrogel
We present large-scale multi-responsive cilia arrays that can be stimulated environmentally (via a pH change), electrically or magnetically. By means of micro-fabrication techniques, we created high-aspect ratio molds on which the polymer solution was cast. The resulting gel structures are stable, highly responsive and their geometry is well controlled. In case of environmentally (pH) or electrically stimulated actuation of the cilia, the size of each individual cilium can be reversibly reduced up to 89%. For a magneto-responsive cilia the maximum cilium end displacement achieved is around 45 µm – for 10 µm thick and 55 µm long cilium – and is only limited by the single cilium length. Such a magnetically-tuneable array could be implemented in bio-mimicking systems, in which collective transport over large areas still remains a challenge. Apart from electro- or magneto- responsive systems a cilia that combine magneto-responsiveness and sensing of environmental pH variations was created. To the best of our knowledge this is the first microfabricated cilia system based on hydrogel that can respond to multiple stimuli (electric field, pH and magnetic field) simultaneously. It is important to stress that our hydrogel cilia molding technique can easily be scaled up to full wafer scale.