How much angle shift can a structural-colour coating shed at a given chroma and oxide mass?

What it found

The 8-layer stacks of garment-stackopt re-optimised on a grid of chroma floors and oxide-mass caps (Nelder–Mead restarts, 3000 calls, 5 seeds per cell). For the red target at a chroma floor of C* 40 the best mean angle shift is 0.68 ΔE₇₆ at a 4.0 g/m² cap, 2.71 at 3.0, and no run is feasible at 2.0 or below; raising the floor to 60 costs more (2.84 at a 4.0 cap). Mass binds before chroma. Stylised: flat substrate, three sample angles, untuned penalties, a coarse grid and a single optimiser, so cell values are noisy and the front is not smooth.

A figure from its own output

Paper, code and results

• README and method
• Experiments and results
• Code
• Tests

More in Engineered clothing

• Does adding layers cut the angle shift of a structural-colour coating at fixed chroma and oxide mass?Layer-count sweep (2 to 12) of the constrained structural-colour coating: six to ten layers reach best angle shifts under 1 dE at C* 40 and 4 g/m2 where 2 and 4 layers stay near 3.4, but 12 layers did not search well at the same budget (stylised, 8 seeds).
• Does an assistive garment pay for its own mass?One-joint ankle exosuit model: active assist cuts modelled whole-body cost 3–14% (gain 0.1–0.5) but a few kg of garment mass erases it; break-even mass ∝ 1/(mass sensitivity). Stylised; assumed constants, no OpenSim/MyoSuite.
• Is it the motor or the battery that decides whether an exosuit pays for its own mass?Adds a motor and battery mass model to the ankle exosuit: at an assumed 8 N m/kg the motor (about 8 kg) makes a gain-0.3 suit raise cost 0.2–1.9%; the sign flips between 8 and 20 N m/kg, battery hours matter little. Stylised; assumed constants.
• Does it pay to move an exosuit's motor and battery from the shank to the waist?Moves the exosuit's motor and battery from shank to waist: the waist layout wins once a shank kg costs more than 1.03–1.39× a waist kg (assumed ratio, swept); at ratio 3 and 8 N m/kg shank +20.7% vs waist +3.3%. Stylised.
• How much cable bend can a waist-mounted exosuit power train tolerate before the shank layout wins?Replaces the assumed Bowden efficiency with the capstan law exp(-mu*theta): at ratio 3 and mu 0.1 the waist layout beats the shank layout until the cable bends through about 31 rad, so friction loss alone does not decide the layout (hysteresis not modelled). Stylised.
• What would a suit-like protective garment weigh and cost, and what limits it?Cunniff-style scaling for nylon, aramid and UHMWPE: at equal weight UHMWPE gives 1.49× aramid's V50 and needs 0.20–0.67× the areal density depending on an unknown exponent; a 3 mm, 1 kg suit-like panel falls short of a 4 kg/m² aramid reference except under optimistic assumptions. Stylised; recalled formula, assumed properties and prices, no protection claim.

All 45 Engineered clothing projects →

Other research topics

Proper scoring & elicitation28Effort & peer prediction9Verification games & slashing19Detection & tolerances14Markets as routers13Prediction-market design9Paying contributors8Decentralised training systems23Digital twins & sim-to-real164LLM chip design loops40Robot manufacturing loops53Ambient AI assistant46Self-replicating manufacturing34Simulation-first design64Engineered clothing45Task-specific AI accelerators40Algorithmic chip-design loops42Open-source purpose-built robots44The software-engineering loop43Adversarial human imitation41Open-source residential construction41Autonomous multi-angle capture34Sensing, imaging and 3D31Energy supply and dense energy storage39Robot societies among people31Agentic co-design of low-cost robots27Laundry-hanging robots25Machine learning on qualitative data23Robots on the building site27Civilizations & group psychology1History & human sciences1

Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.