The overarching goal of this project is to understand the biomechanical principles of proboscis self-assembly and to apply these principles to engineer fiber-based self- assembling microfluidic devices for manipulation of micro and nano droplets. The model system under investigation is the proboscis feeding tube of butterflies. This tube is assembled and hardened after emergence of the adult from the pupal encasement by joining dorsal and ventral galeae fibers and cuticle hardening. The mature proboscis is coiled but can be fully extended during the feeding process; the extension involves antiparallel sliding of the galeae fibers. The goals of the project are (i) to study the effect of saliva in creating capillary pressure that forces the two galeae together (the elasto-capillary effect) in live butterflies and a model system of fiber rails, (ii) to study saliva behavior during this process of proboscis assembly, using X-ray phase-contrast imaging, (iii) to provide full characterization of mechanical and wetting properties of the proboscis to evaluate the model parameters and assess the applicability of different self-assembling and hardening scenarios, and (iv) to develop a fiber-rail type microfluidic system that that relies on capillary action and would work on the principles of proboscis assembly/disassembly.
