  This work describes a mechanical approach for manipulating the capillary
length and spreading of liquid coatings on flexible substrates with high
gravity. Experimental verification in the literature has focused on cases under
standard gravity on earth, and to the authors' knowledge, this work is the
first to explore its relevance to spreading puddles under high gravity. By
using centrifugation with a high-density liquid base underneath a coated
substrate, it is possible to apply acceleration normal to a substrate to
decrease the capillary length and increase the rate of spreading. Due to the
nature of centrifugation, this method works primarily on flexible substrates,
which bend with a curvature that conforms to a contour of uniformly distributed
centrifugal acceleration. With high gravity of 600 g applied, the capillary
length reduces by a factor of 24.5, and the spreading shifts from "transient
spreading" between the surface tension-driven and gravity-driven regimes to the
gravity-driven regime. Experimental results show that high gravitational
acceleration will enhance the rate of spreading such that a puddle, which would
require 12 hours under standard gravity on earth to go from an 8-{\mu}l droplet
to a 40-{\mu}m thick puddle, would require less than 1 minute under 600 g.
Overall, this work suggests that previously derived expressions for
gravity-driven spreading of puddles under earth's standard gravity extend to
predicting the behavior of puddles spreading on smooth, wetting substrates
exposed to more than 100 g's of acceleration.
