Fig. 5. Propulsion of the acoustic microrobots on the 3D topographical surface of the epithelium cellular layer in vitro.
(A) Confocal microscopy image of the epithelium layer that was used as a 3D topographical surface for locomotion of microrobots. Scale bar, 100 μm. (B) Height heatmap of the epithelium layer surface measured by a confocal microscope, with a peak height of the cell nuclei between 2 and 4 μm. Scale bar, 100 μm. The height profile for two representative lines, denoted by H1 and H2, depicts the complex 3D topography of the cell layer. (C) Time-lapse images of the acoustic microrobot propulsion on the epithelium cells during 1.5 s, under ultrasound actuation of 380 kHz and 2 Vpp. Scale bar, 30 μm.