Figure 4.

Digital magnetofluidic operations: Complex transport and fusion. A) The magnet was placed at a distance of 12 mm from the surface of a 100 mm HoCl₃ substrate and manually moved to direct the motion of a 5 μL mineral oil drop (left). Superposition of images (middle, each image separated by 8.6 s, scale bar=2 cm) and XY positions of the drop as a function of time (right) for an imposed S‐shaped trajectory. The corresponding video is provided as Movie S4. B) Two identical magnets were placed at a distance of 10 mm and moved manually to direct the motion of two 5 μL mineral oil drops, without (drop A) and with (drop B) Sudan II dye, and induce their fusion (left). Images show the magnetically induced drop fusion (right). The scale bar=1 cm. The corresponding video is provided as Movie S6.