Fig. 3: Demonstration for EPD’s generality with various liquids, including different droplet volumes, liquid conductivities, and liquid relative permittivities.

A Schematic diagram of EPD’s generality with various liquids. B EPD-based actuation of droplets with volumes ranging from nanoliters to milliliters. The maximum actuation velocity increases with droplet volume under a two-thirds power relationship. Scale bars: 5 mm. Error bars, SD. C Simulated Maxwell stress tensor applied on droplets with different conductivities \(\sigma\), showing that the generated EPD force applied on droplet does not change with conductivity. D Simulated Maxwell stress tensor applied on droplets with different relative permittivities \({\varepsilon }_{r}\) (solid lines). The calculated Maxwell stress tensor for the liquid with minimum relative permittivity of 1.8 at normal temperature and pressure (NTP) (purple line) is still much larger than the minimum force required for effective actuation (blue dash line), thus indicating that EPD has the potential to manipulate all types of liquids. E Optical images of EPD-based droplet actuation, including three common inorganic liquids as well as three common organic liquids, including alkane, alcohol, and ester. Scale bars: 5 mm. F Simulated effective actuation distance of water, triacetin, and paraffin (star symbol) obtained from the crossing between the calculated Maxwell stress tensor (solid line) and the minimum force required for effective actuation (dash line). G Comparison between the simulated and the measured effective actuation distance (EAD), demonstrating the validity of the simulation result. Error bars, SD (n = 3). Source data are provided as a Source Data file.