Fig. 5.

Light-induced actuation. a Upon focusing a femtosecond laser on one of the bases, the corresponding bi-material beam bends strongly, whereas the adjacent structures show only a weak response. Upon switching off the light, the structure moves back to its original position. This behavior is repeatable. A calculated temperature profile (see false-color scale on the right) is overlaid onto the measured optical micrographs. b Cross-sections through such temperature profiles in the water bath. At t = 0 a constant temperature is assumed for the base, whereas the outside stays at ambient conditions. With increasing time (see legend) heat diffuses away from the base, however, the temperature rise at the adjacent structures is too small for significant actuation (compare Fig. 3b). Scale bar is 50 µm