Extended Data Fig. 2: Negative deflection and adhesion of films into microwells.

(A-B) Optical micrographs of 35-nm 2DPA-1 film transferred onto silicon oxide substrate with a 50 °C annealing step implemented prior to etching away the polystyrene support layer. Wells with brown coloration indicate films that collapsed into the bottom of the well rather than suspend. (C) Corresponding atomic force microscopy (AFM) profiles, taken horizontally, of the microwells highlighted with the dashed white circles in panels A and B. (D) Comparison of bulge profiles for a completely dimpled film (red), representing a negative pressure differential, against a positively deflected film that is adhered into the microwell (blue), representing a positive pressure differential. The adhesion length is assigned as the distance between the top of the microwell and the minimum value of the positively deflected film (dashed line). (E) Histogram of the film depth into well attributed to the total deflection (solid bars) and adhesion to the inner wall of the well (hatched bars).