Bioinspired synthetic molecular machines: from actuation to recognition
In his thesis, Adrien Combe develops tiny machines inspired by living things, controlled by light. A flash changes the shape of a molecule, which dictates how the molecules assemble, and the whole phenomenon produces an action: either it moves (actuation), or it attaches to proteins (recognition). Everything is designed for aqueous media, in conditions close to physiological, and with bio-sourced building blocks when possible.
Combe begins with an overview: how Nature uses light and how to mimic it, with three simple rules: aqueous environment, non-toxic light, low environmental side-effects. Then, a flexible artificial muscle: soft materials bend under light and return on their own in the dark.
Next, Combe describes how motors decorated with sugars modulate, in light, the attachment of human lectins without changing the sugar: a true ON/OFF control of biological recognition. Subsequently, other “sweet” motors organize themselves, depending on their shape, into micelles, filaments, particles, or sheets. The exposure of the sugars varies, providing active surfaces on demand. Thereafter, Combe identifies which shapes bind specifically to the model protein ConA: micelles and filaments attach and deactivate with free sugars; particles and sheets stick together rather randomly.
Finally, a bio-based molecule can, under UV or blue light, switch or lock into another shape. Calculations explain these pathways and guide greener designs.
Light controls shape, shape controls assembly, assembly controls function. The next step is near-infrared light, cell applications, more natural raw materials, toward miniature soft robots, adaptive medical coatings, and light-driven functions.