Fig. 5: Coiled MSP bundles.
From: Self-spinning filaments for autonomously linked microfibers
a Fluorescence micrographs of substrate-bound, aligned MSP arrays with ϕ = 14° (top), 46° (center), and 76° (bottom); scale bars 200 μm. b–d 3D-reconstructed confocal z-stacks (right) of bundles arising from coincident and proximal MSP coiling with (ϕ,n) = (14°,4) (b), (46°,7) (c), and (76°,10) (d). The dashed box in d denotes a branch with n = 1; scale bars b–d 100 μm. e smoothed rendering of constituent MSP centerlines in bundles b–d; linking number increases with n. f Width-normalized pitch as function of width-normalized radius; the lower dimensional limit for an n-ply bundle is schematically indicated for n = 1–6 and is independent of helix chirality; data describes ‘single’ MSP helices and the constituent MSPs in bundles b–d indicating that constituent MSPs in b–d adopt dimensions of ideal 1, 2, or 3-ply structures. Error bars represent quadrature sum of rms displacement from the fitted helix (pitch, radius) with 1 standard deviation in measured MSP width.
