Fig. 4: Toughness and anti-fatigue properties.
From: Superstretchable, yet stiff, fatigue-resistant ligament-like elastomers
a Fracture energy of MEG2-Li. b Stress-strain curves of original and healed specimens for different healing times at room temperature. c Optical microscope images of a cut MEG2-Li specimen healing for various times at room temperature. d Photos of the initial notched specimen (N = 1, λ = 100%) (i) and the notched specimen after 5,000 cycles (ii) (N = 5,000, λ = 337.5%) and after 10,000 cycles (iii) (N= 10,000, λ = 337.5%). e Crack propagation per loading cycle (dc/dN) plotted against energy release rate (λ = 312.5%, 322.5%, 337.5%, 350%, 362.5%, 375%). f, Photos of PDMS specimen as ligaments bent 90o for 10 times and broken: 1. initial 2. bent 90o 3. the specimen returned to the vertical state 4. the magnified pictures for the broken ligament after 10 cycles. g Photos of MEG2-Li specimen as ligaments bent 90o for 10,000 times: 1. initial 2. bent 90o 3. the specimen returned to the vertical state 4. the magnified pictures for intact ligaments after 10,000 cycles.
