Figure 1. Bi-conductive surfaces to tailor spatial variations in wall temperature.

The fabricated surfaces showing (a) samples with two and twelve divisions per centimeter, and (b–d) scanning electron microscope (SEM) images of the low-conductivity epoxy divisions embedded in high-conductivity copper. (e) Schematic of the resulting flow field where spatial variations in wall superheat temperature, ΔT(x), promotes spatial ordering. Nucleation sites, as well as the liquid and vapor flow paths, are tailored to coincide with the wavelength of the in-plane temperature variations given by the pitch, P. (f) Image of the onset of nucleate boiling (ΔT ~ 5 K), where bubbles preferentially nucleate in the center of the copper segments resulting in (g) control over the nominal bubble diameter during lateral coalescence.