Criteria for avoiding collapse in soft systems

In soft systems, unwanted collapse may occur even without external loading due to adhesion. Analytic models are developed for collapse in two representative contexts: soft lithography and epidermal microfluidic devices, using fracture mechanics and beam/plate theory, respectively. In both cases, it is shown that a single parameter, the normalized work of adhesion, that combines the effect of geometry, stiffness of the material and work of adhesion governs different collapse states (no collapse, meta stable collapse and stable collapse). The established criteria provide important guidance to avoid collapse in the systems discussed.