Active materials that respond to physical1, 2, 3 and chemical4, 5, 6 stimuli can be used to build dynamic micromachines that lie at the interface between biological systems and engineered devices7, 8. In principle, the specific hybridization of DNA can be used to form a library of independent, chemically driven actuators for use in such microrobotic applications and could lead to device capabilities that are not possible with polymer- or metal-layer-based approaches. Here, we report shape changing films9 that are powered by DNA strand exchange reactions with two different domains that can respond to distinct chemical signals. The films are formed from DNA-grafted gold nanoparticles10, 11 using a layer-by-layer deposition process. Films consisting of an active and a passive layer show rapid, reversible curling in response to stimulus DNA strands added to solution. Films consisting of two independently addressable active layers display a complex suite of repeatable transformations, involving eight mechanochemical states and incorporating self-righting behaviour.
At a glance
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- Supplementary information (1.07 MB)
- Supplementary Movie 1 (28.5 MB)
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- Supplementary Movie 2 (11.8 MB)
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- Supplementary Movie 7 (53.7 MB)
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