Fig. 6

Using applied electric fields \({{\bf{E}}}_{{\rm{A}}}\) to actuate TMD alloy monolayers with composition-programmed shapes. a Schematics of how Janus regions in monolayers with clamped edges reorient, bend, or flatten according to their electric polarity relative to that of the field. Gray, magenta, and cyan spheres represent Mo, S, and Se atoms, respectively. Gray (black) arrows indicate atomic dipole moment (applied electric field) direction. The first column shows equilibrium shapes of seven Janus-patterned free standing sheets in the absence of an applied electric field (\({{\bf{E}}}_{{\rm{A}}}=0\)). b–h Simulated shapes of Janus-patterned MoSeS monolayers under uniform fields with directions shown in (a). i\(\pm {{\bf{E}}}_{x}\)-induced crumpling of a monolayer containing circular Janus domains arranged on a square lattice with randomly assigned polarity. j \({{\bf{E}}}_{x}\)-induced two-scale buckling/folding of a patterned monolayer containing zigzag Janus domains on two length scales. Also see Supplementary Movies 6–26