Figure 1

(a) Scanning electron micrograph of a Mikromasch TL01 cantilever. Scale bar $20\mu \mathrm{m}$. (b) Flexural thermal noise spectrum around the first flexural resonance (resonant frequency $\sim 101\mathrm{kHz}$, quality factor $\sim 280$) of a TL01 cantilever. The deflection noise floor is taken to be the baseline around the resonant peak; $512\mathrm{fm}/\sqrt{\mathrm{Hz}}$. (c) Torsional thermal noise spectrum around the first torsional resonance (resonant frequency $\sim 1.1\mathrm{MHz}$, quality factor $\sim 900$) of the same TL01 cantilever as in Fig. 1b, taken on the same AFM with the same laser alignment. The noise floor is $40\mathrm{fm}/\sqrt{\mathrm{Hz}}$.Reuse & Permissions

Figure 2

(a) Overview of a sheared polyethylene film. The shearing direction is along the diagonal from bottom right to top left. Height image, lit from the side in order to delineate the facets. Scale bar 100 nm. (b) Histogram of the lengths of facets on the lamella surface measured from Fig. 2a. (c) High resolution phase image showing the (110) surface of a crystalline polyethylene lamella. The image is rendered in pseudo-$3d$, black to white scale 10°. Scale bar 5 nm. (d) High resolution phase image of a lamella whose the surface corresponds to the (010) plane of the polyethylene crystal. The image is rendered in pseudo $3d$, black to white scale 10°. Scale bar 5 nm. (e) Cross-section along the dotted line on Fig. 2d. The lower peaks are due to the central chain in the unit cell. The cross-section is averaged over 17 lines parallel with the dotted line indicated.Reuse & Permissions

Figure 3

(a) High resolution phase image showing a chain that folds and reenters the crystal before reaching the edge of the lamella (arrow). Black to white scale 18°. Scale bar 5 nm. (b) High resolution phase image showing a chain whose end has deposited in the center of a lamella. Black to white scale 15°. Scale bar 5 nm.Reuse & Permissions

Figure 4

(a) Histogram of crystalline chain lengths (normalized to the mean thickness of their respective lamellae to remove issues with drift) measured from individual chains visible in 3 different lamellae. The bin width corresponds to $\sim 6\AA$. (b) Phase image showing the interface between the edge of a crystalline lamella and the amorphous phase. Chains in the (010) surface of the crystal are resolved at the top right of the frame. The upper surface of the central region of the lamella is believed to be the (110), which is not resolved here. Free loops emanating from the fold surface project into the amorphous region (dashed box). Black to white scale 25°. Scale bar 10 nm.Reuse & Permissions