Figure 2. Nucleate boiling on bi-conductive surfaces.

High-speed imaging of nucleate boiling at ~10–15 W/cm² on (a) a bare copper surface and bi-conductive surfaces with (b) N = 4 cm⁻¹, (c) N = 6 cm⁻¹, and (d) N = 12 cm⁻¹ designs. For each bi-conductive surface, nucleation is seen in the center of the high-temperature copper and no lateral motion of the three-phase contact lines beneath vapor bubbles is observed. The low-temperature epoxy divisions remain wetted at all times providing ordered pathways near the surface for replenishing liquid to feed the bubble ebullition cycles. See supplementary information for complete movies.