Abstract
Filamentous bundles are ubiquitous in Nature, achieving highly adaptive functions and structural integrity from assembly of diverse mesoscale supramolecular elements. Engineering routes to synthetic, topologically integrated analogs demands precisely coordinated control of multiple filaments’ shapes and positions, a major challenge when performed without complex machinery or labor-intensive processing. Here, we demonstrate a photocreasing design that encodes local curvature and twist into mesoscale polymer filaments, enabling their programmed transformation into target 3-dimensional geometries. Importantly, patterned photocreasing of filament arrays drives autonomous spinning to form linked filament bundles that are highly entangled and structurally robust. In individual filaments, photocreases unlock paths to arbitrary, 3-dimensional curves in space. Collectively, photocrease-mediated bundling establishes a transformative paradigm enabling smart, self-assembled mesostructures that mimic performance-differentiating structures in Nature (e.g., tendon and muscle fiber) and the macro-engineered world (e.g., rope).
Content

Supplementary material

Supporting Material
Supplementary document including supplementary methods description, figures and schemes, and descriptions of supplementary movies.

Movie S1
Scanning the length of the helix in Figure S5a,d; counterclockwise rotation confirms left-handed chirality.

Movie S2
Scanning the length of the helix in Figure S5b,e; clockwise rotation confirms right-handed chirality.

Movie S3
A coiling array of copolymer 2 MSPs in pH 8 buffer solution with photocrease dose of 25 J cm-2 (lmax = 365 nm). Scale bar 500 μm. 1x playback speed.

Movie S4
A coiling array of copolymer 2 MSPs in pH 8 buffer solution with photocrease dose of 75 J cm-2 (lmax = 365 nm). Scale bar 500 μm. 1x playback speed.

Movie S5
Deflection of copolymer 2 MSPs of h0 ~ 1 μm without photopatterning and after release into aqueous solution; MSPs do not spontaneously coil and are elastically bent in flow. Scale bar 500 μm. 1x playback speed.

Movie S6
Deflection of copolymer 3 MSPs of h0 ~ 1 μm after patterning with photocrease tilt angle ~ 45° and release into pH 8 buffer solution; MSPs do not spontaneously coil and are elastically bent in flow. Scale bar 200 μm. 1x playback speed.

Movie S7
Deflection of copolymer 3 MSPs of h0 ~ 1 μm after patterning with photocrease tilt angle ~ 45° and release into pH 8 buffer solution; MSPs do not spontaneously coil and are elastically bent in flow. Scale bar 200 μm. 1x playback speed.

Movie S8
Release and coiling of a photocreased MSP array in pH 8 buffer with d = 60 μm and f = 44°. Scale bar 500 μm. 1x playback speed.

Movie S9
Bending a 5-MSP bundle (f = 18° and h0,avg = 0.84 μm) in pH 8 buffer with 3 mM sodium dodecyl sulfate via suction at 500 μL min-1 through a capillary tube. Scale bar 1 mm. 5x playback speed.

Movie S10
Bending a single MSP helix (f = 18° and and h0 = 0.98 μm) in pH 8 buffer with 3 mM sodium dodecyl sulfate via suction at 300 μL min-1 through a capillary tube. Scale bar 1 mm. 5x playback speed.