Capillary control of composite rafting

Elastic plates floating on a fluid substrate, and subjected to axial compression, display a sinusoidal pattern in their vertical displacement, called wrinkles. We examine the wrinkles of inhomogeneous soft composite thin sheets lying on a liquid. In particular, we consider effective medium behaviour theories to predict the bending stiffness of a composite plate consisting of a soft host with liquid inclusions both large and small relative to the elastocapillarity length. By imposing a gradient of the volume fraction or varying the inclusion size, we can devise elastic sheets with a varying stiffness and therefore deliberately manipulate the nature of the emerging wrinkles for different lengths of the plate.