Over the course of this project, we have made several breakthroughs in designing and understanding mechanically active supramolecular systems. Together, these achievements establish the foundations of a new field where artificial molecular assemblies can generate, transmit, and withstand mechanical forces in fluid environments, ultimately mimicking and complementing the functional roles of cytoskeletal polymers.
1. Interfacing and crosslinking self-assembled tubes
To harness mechanical forces effectively, supramolecular fibers must be connected to the structures on which they act. We developed strategies for interfacing and crosslinking tubular assemblies, thereby amplifying the collective action of multiple molecular machines. These insights also advance the broader understanding of crosslinking and interaction in supramolecular polymers, with implications for soft materials design.
2. Light-fuelled self-assembly into tubular architectures
We established non-equilibrium self-assembly pathways where tubular supramolecular polymers are maintained in dynamic steady states driven by light. These assemblies undergo rapid cycles of growth and disassembly, operating at rates sufficient to generate mechanical work in fluid. This demonstrates that supramolecular systems can be fuelled and controlled externally to emulate the dynamic behavior of cytoskeletal filaments.
3. Mechanical properties of supramolecular hydrogel networks
We explored the mechanical properties of stiff tubular fibers assembled into hydrogels. These networks exhibit strain stiffening under stress, analogous to collagen and fibrin, followed by plastic deformation that preserves network integrity. This discovery of structural plasticity in purely supramolecular systems provides a new paradigm for designing adaptive and resilient biomimetic materials.
4. Depolymerization motors as microscopic machines
We realized the first artificial depolymerization motors, capable of exerting mechanical forces through directional disassembly. These forces are sufficient to drag microscopic particles against fluid flow, directly paralleling the role of microtubules during cell division. This achievement represents one of the first demonstrations of a synthetic microscopic machine performing work in fluid, opening the way toward molecular robotics and programmable manipulation of matter at the microscale.
