Fig. 3
From: Spontaneous jumping, bouncing and trampolining of hydrogel drops on a heated plate
Effects of surface wettability, dwell time, and modulus on jumping. a Map of outcomes for heating of 25 kPa hydrogels on b superhydrophobic, c hydrophobic, and d hydrophilic surfaces with corresponding optical images before heating. Data are denoted as meniscus jumping (filled), jumping after burning (unfilled), sliding (blue grid), and Leidenfrost (green diamond). SEM images of (e) PTFE-coated TiO2 surface and (f) unmodified tungsten surface. Scale bar: 3 µm. g Zoom in of 25 kPa hydrogel and hydrophilic tungsten interface being burned away (greater than 3 min dwell time). The white spot in the center of the hydrogel is reflection from light. The white dotted line is the interface between the hydrogel and surface. A cavity (dashed blue arrows) initiates and as the plate temperature continues to increase, the interface forms a vapor layer that separates the drop from the surface. Scale bar: 0.5 mm. h Map of outcomes for 2 kPa hydrogels on i superhydrophobic, j hydrophobic, and k hydrophilic surfaces with corresponding optical images before heating. Scale bar: 1 mm
