It Takes Two to Make a Thing Go Right: Boosting Current in Coupled Motors

This .zip archive includes the source code, simulation scripts and parameter settings, figure-generation scripts, and figures used in our manuscript, “It Takes Two to Make a Thing Go Right: Boosting Current in Coupled Motors.”Additional details are available in the README.md files within the archive. Manuscript abstract: Catalysis-driven synthetic molecular motors operate in a loose mechanochemical coupling regime, one in which a decomposition of a fuel molecule does not reliably produce a forward step. In that regime, stochastic backward steps can significantly degrade the motor's current, prompting us to ask whether mechanically coupling multiple such motors can boost their averaged current. By simulating rotaxane-based motors with two classes of models\textemdash particle-based nonequilibrium molecular dynamics and jump-diffusion models\textemdash we show that current boosts are physically achievable. Our observed boosts, which amplify current by single-digit factors, emerge when coupling between motors can increase the activity, speeding up the rate of both forward and backward steps. In doing so, the bias for preferring forward steps actually degrades, but the lost bias can be largely recovered by raising the fuel concentration, demonstrating a general design strategy: amplify activity through coupling and restore bias through stronger driving.