Influence of hydration on the mechanical performance of duck down feathers.

1. We report the first measurements to be made on the effects of hydration on the mechanical properties of commercially-prepared duck down feathers. Tensile tests were performed, to failure, on isolated barbs of down feathers at 50% RH and with fully-hydrated (wet) feathers. 2. The Young's modulus (stiffness) and ultimate stress (strength) of the feathers was higher at 50% RH than when wet. Wet feathers, however, failed at greater extension than dry feathers. The implications for down feather performance and for the use of feathers as a structural material are discussed.