Fig. 1. Fabrication of thermo-responsive reconfigurable dumbbells.

a Scheme of the deposition of polystyrene (PS) particles (step 1) and PNIPAM-co-MAA microgels (step 2) onto a PDMS template patterned with 2 × 4 μm² size traps. The arrow indicates the direction of the deposition. Particles are accumulated at the meniscus of the moving droplet and deposited into the traps via capillary forces. b AFM image in the water showing PS-microgel dumbbells in the traps before harvesting. The bright spheres are the PS colloids and the darker ones are the swollen microgels. c, d Schematic representation c and optical micrographs d of the light-driven reconfiguration of a dumbbell. Fluorescent illumination with a power density ρ_FL = 54 mW(mm)⁻² locally increases the temperature above the VPTT of the microgel, causing it to deswell and correspondingly induce a variation of the dumbbell’s geometry and dielectric properties. The transition is reversible upon removing the incident light. Scale bars: 2 μm.