This project draws inspiration from the sinuous motion of a lamprey, in which neurons running down the spinal column are excited in sequence causing the musculature to contract, thereby propelling the lamprey. The fundamental principles underlying this behavior are understood, and this team seeks to engineer nonliving materials that possess these properties of living matter. They will develop purely synthetic materials that will operate autonomously, driven solely by chemistry without electricity, computers, or motors. These materials will execute multiple functions and be externally triggered to modify their behavior. Thus, this work will establish a new paradigm of precise and programmable chemical control for the fledgling field of soft robotics, in which soft, tissue-like materials replace the rigid, hard materials now found in robots on factory floors.
The objective of the project is to develop purely synthetic, chemomechanical materials that emulate biological processes, such as the beating of a heart, at programmable rates and rhythms. The long-term goal is to elucidate the fundamental physical principles of active soft matter based on reaction-diffusion chemistry, enabling engineering of materials capable of chemical control and chemomechanical transduction. This research will address two fundamental challenges in the design of chemomechanical materials. The first is to understand and develop mechanisms of volume transitions in redox-sensitive gels, by which forces can be actuated. Materials engineered from a selection of promising building blocks will be probed over length scales ranging from nanometers to millimeters in order to fully elucidate gel structure and dynamics. These findings will be fed into atomistic and mesoscopic computer models, which will in turn inform the chemical synthesis of next-generation materials with desirable properties. The second challenge is to engineer a control mechanism comprised of an array of micron-scale compartmentalized reactors that contain an oscillating chemical reaction, and are physically networked via diffusion. Coupling the control and actuation sub-systems will yield chemically responsive gels that can change volume in concert with predictable and tunable chemical activity. Such materials will have attributes heretofore found only in living matter, such as flexibility in mammalian tongues, pulsatile contractions in human intestines, and heliotropism in plants. Thus, this work will establish a new paradigm of precise and programmable chemomechanical control for the fledgling field of soft robotics.
