Integrated Calendar

Over a century ago, various experiments both in gravitropism and phototropism, revealed that plants respond to an integrated history of stimuli rather than responding instantaneously. Particularly, experimental observations have shown that plants respond identically to different combinations of stimuli - intermittent in time or with reciprocal ratios of intensity and duration - as long as the total dose of these stimuli is the same. Current mathematical descriptions of the kinematics of tropic
responses are instantaneous and limited to constant stimuli. In this work we adopt the well-established approach of response theory, which describes the non-trivial input-output relationship of a signal transducer, in this case a plant turning an external stimulus into a growth response. This model is experimentally tractable, allowing a quantitative description of the ability of plants to integrate stimuli over time, laying the foundation for an understanding of decision-making in plant tropisms.

Engineering next-generation materials that can grow into efficient multitasking agents, move rapidly, or discern environmental cues greatly benefits from inspiration from biological systems. In the first part of my talk, I will present a geometrical theory that explains the biomineralization-inspired growth and form of carbonate-silica microarchitectures in a dynamic reaction-diffusion system. The theory predicts new self-assembly pathways of intricate morphologies and thereby guides the synthesis of light-guiding optical structures. The second part is dedicated to a soft matter analog of controlled actuation and complex sensing in living systems. Specifically, I will introduce a continuum framework of a simple hydrogel system that is activated upon transport and reaction of chemical stimuli. The hydrogel exhibits unique cascades of mechanical and optical responses, suggesting that common gels have a much larger sensing space than currently employed. The theoretical work presented in my talk is intimately connected to modern materials science. The effective convergence of theory and experiment paves the way for optimized hard or soft biomimetic materials for applications ranging from bottom-up manufacturing to soft robotics.