Solid/solid interfacial interactions have been successfully characterised using the Johnson, Kendall, and Roberts (JKR) analysis for many years now. Following a suggestion and accompanying analysis by the present author to replace a solid sphere by a gas-filled, hollow, spherical membrane in contact experiments, we now propose a liquid-filled "balloon." Free energy changes due to stretching, bending, the mechanical contact force and adhesion are assessed and minimised to obtain an exploitable equation permitting estimation of the energy of adhesion of the system as a function of various, in principle more easily measured, parameters.