Here 𝐾 0 is a fitting parameter, the factor of two accounts for the fluid flow around each particle, and a negative relative velocity corresponds to particle separation. The force balance utilizes previously derived scaling arguments for 𝑈 𝐸𝐻𝐷 and 𝑈 𝐸𝑂 (𝑝𝐻) with slight modifications (See Supplementary Note 2 for details). The EHD flow scaling model includes the single fitting parameter, 𝐾 0 , which prior work has shown is necessary to match the scaling result to experimental measurements . The fitting parameter had a typical value of 𝐾 0 ≈ 0.01 in prior works.