Extended Data Fig. 5: The cutting process in water units.
From: Reconfigurable liquid devices from liquid building blocks
a, Photos of a water channel before and after being cut off with a fluorinated paper sheet. The red and blue points revealed the positions of tri-phase contact points from top view. Scale bars: 1 mm. b-d, A simplified model for the cutting process. b, The top view of a thin water layer when the water unit is completely cut off by a fluorinated paper sheet. c, The cross-sectional view of a thin water layer during the cutting process. d, A simplified model for the calculation of \(\Delta {p}_{1}\) in (c). \(\Delta p\): the Laplace pressure of the curved water–oil interface. \(\gamma\): the surface tension of water. \({r}_{{\rm{p}}}\): the radius of the pillar. \(l\): the distance between pillar centers. \(\theta\): the WCA of the substrate material. \(\alpha\): the angle indicating the position of the water–oil interface in the pillar array. \(\beta\): the WCA of the hydrophobic paper sheet. \({F}_{{up}}\) and \({F}_{{down}}\): the upward and downward forces borne by the water–oil interface on the paper sheet, respectively. More details see Supplementary Note 3.
