Figure 5: Photothermal heating of HAIRS-xNR samples.

(a) Photothermal response in HAIRS-xNR samples with different AuNR concentrations irradiated at a constant power (∼11 mW). The pink dashed circles mark the area where the microstructures are actuated. (b) Sample image taken from the beginning of a movie sequence recorded during an experiment with repeated 5 s ‘ON’ (∼18 mW) and 5 s ‘OFF’ illumination cycles of a HAIRS-50NR sample (Supplementary Movie 4). The blue dashed line marks where the bending direction of the microplates reverses. The movement of microplates located at different distances from the dashed line was tracked over multiple actuation cycles in HAIRS-15NR, HAIRS-30NR and HAIRS-50NR samples to characterize their displacement profiles. (c) Displacement as a function of the distance from the central line where the bending direction of the microplates reverses. The movement of the microstructures #1, #3 and #6 (labelled in (b)) over time in a HAIRS-50NR sample (Supplementary Movie 4) is shown. (d) Displacement as a function of the AuNR concentration. The movement of the microstructure #3 (labelled in (b)) during a single actuation cycle for HAIRS-15NR, HAIRS-30NR (Supplementary Movie 3), and HAIRS-50NR (Supplementary Movie 4) samples is shown. (e) Image taken from a movie sequence where the HAIRS-xNR sample was moved as the NIR laser was kept focused on the same spot. The black arrows track the motion of the sample. All scale bars are 10 μm.