Figure 5.

Cyclical strains of native and of ion-exchanged single silk fibres. (a) After the first conditioning cycle to 20% of a native fibre (black curve), subsequent cycles were superimposable on one another (coloured). The fibres were rested, unstrained, for 2 h between cycles. (b) The average cyclical force–elongation profile of three fibres exchanged with the indicated ion (solid lines). The shaded bands represent the s.d. (n = 3). (c) The percentage change in initial modulus and hysteresis from the control cycle values. Error bars represent the s.d. (n = 3).