To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie S3. Manipulation of red- and blue-dyed (commercial food coloring used) aqueous droplets suspended in the oil-based yield-stress fluid. A hydrophobically modified stainless-steel needle pushes the droplets into contact but they do not combine. Embedded droplet printing in yield-stress fluids Arif Z. Nelson, Binu Kundukad, Wai Kuan Wong, Saif A. Khan, and Patrick S. Doyle PNAS. 2020. 117:5671-5679 DOI: 10.1073/pnas.1919363117 Download Original Video Browse All Videos »