CBE Seminar: “Engineering Soft Matter Systems through the Lens of Plant Physiology” (Jean-François Louf, Auburn University)

Abstract:

Plants sense local pressure changes in their vasculature and transmit them across tissues via poroelastic coupling, triggering ionic currents in distant mechanosensitive cells to guide growth and biochemical responses. Inspired by this natural mechanotransduction, my lab develops synthetic analogs across soft materials. I will first present a soft robotic skin that mimics plant vasculature, where mechanical strain generates overpressure in embedded channels to enable remote contact detection and stiffness sensing; this frugal science tool, built for under $50, can measure the Young’s modulus of soft objects, serving as a low-cost alternative to commercial mechanical testers. Next, I will introduce a piezoionic hydrogel that transduces pressure into ionic fluxes, acting as a mechano-ionic interface suitable for biointerfacing with tissues like the heart, where mechanical and ionic signaling are intrinsically coupled. Notably, our material generates ionic currents stronger than any reported to date, enabling direct interfacing with neurons without the need for amplification. Lastly, I will discuss our work on hydrogel-coated seeds, which resolves a longstanding agricultural conundrum: while such coatings have been inconsistently beneficial, we show that the key determinant is not hydration rate, as commonly assumed, but gas permeability—since the coating can block oxygen entry through the micropyle and hilum, delaying germination in some species. Together, these projects illustrate how plant-inspired poroelastic mechanisms can inform the design of soft sensors, actuators, and controlled-release systems.