A nanomechanical device based on linear molecular motors

An array of microcantilever beams, coated with a self-assembled monolayer of bistable, redox-controllable [3]rotaxane molecules, undergoes controllable and reversible bending when it is exposed to chemical oxidants and reductants. Conversely, beams that are coated with a redox-active but mechanically inert control compound do not display the same bending. A series of control experiments and rational assessments preclude the influence of heat, photothermal effects, and pH variation as potential mechanisms of beam bending. Along with a simple calculation from a force balance diagram, these observations support the hypothesis that the cumulative nanoscale movements within surface-bound “molecular muscles” can be harnessed to perform larger-scale mechanical work.