was proved reversible by light irradiation. This work is a significant step for the
design of smart surfaces with switchable wettability in a light-controlled fashion.
Our group reported the successful construction of a muscle-like molecular actuator based on [c2] daisy chain rotaxane to reversibly modulate the gap distance
between two linked gold (Au) NPs [64]. As shown in Fig. 11, this molecular muscle
actuator enables the equipped Au NPs with stimuli-responsive capability through the
acid-/base-powered molecular transformation. Although many efforts have been
successfully put into transforming artificial molecular muscles from microscopic
molecular scale to macroscopic polymer scale [35], this groundbreaking work
realized nanostructure manipulation by muscle-like molecular actuator – a couple
of Au NPs linked by the molecular actuators can be reversibly switched with
addressable gap distance that is correlated with the length of molecular actuator.
This research represents a brighter functionalization and application of artificial
Fig. 11 Schematic operation mode of the [c2]daisy chain-based muscle-like molecular actuator for
the Au NPs [64] (d represents the distance between the two Au NPs in different states)
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