  Superhydrophobic surfaces with multi-scale topographies offer exceptionally
high apparent water contact angles and low contact angle hysteresis by virtue
of the small liquid{\textendash}solid contact fractions they enable. Natural
water-repellent surfaces such as lotus leaves often feature dome-shaped
micro-scale protrusions, whose lack of sharp edges also facilitates smooth
droplet shedding without pinning. Engineered hydrophobic surfaces, however,
have not yet fully exploited the merits of protrusions with controlled
curvature. In this work, thermal re-flow of photoresist patterns followed by
elastomeric casting was used to fabricate arrays of micro-domes with sizes
20{\textendash}50 {\mu}m. These microstructures were coated with a nanoporous
zinc oxide film and fluorosilanized to produce hierarchical surface
topographies with static water contact angles up to 169.7{\pm}0.4{\deg} and
contact angle hysteresis as low as 14.7{\pm}1.3{\deg}. Performance of the
micro-dome arrays significantly exceeded that of arrays of sharp-edged square
pillars and flat surfaces coated with the same nanoporous film. The highest
performance came from the smallest micro-domes (20 {\mu}m) and closest spacings
(10 {\mu}m) investigated. For larger features, contact angles reduced and
hysteresis increased {\textemdash} unexpected trends not explained by contact
fraction alone. This simple fabrication technique could be adapted to
manufacture large surfaces for droplet shedding, including in heat transfer
applications.
