Fig. 2: Temperature-dependent mechanical properties of the complexed R32 hydrogels.
From: Programmable adhesion and morphing of protein hydrogels for underwater robots
a The storage modulus (E′) and loss factor (tan δ) as a function of temperature of the hydrogels. R32-SiW, R32-5%-SiW, R32-15%-SiW and R32-30%-SiW correspond to the SiW-complexed hydrogels with a di-tyrosine crosslinking degree at 0, 5%, 15% and 30%, respectively. b The Young′s modulus and breaking strain of the hydrogels measured by tensile tests at various temperatures. The error bars represent the standard deviations of triplicates. c The proposed mechanism of the switchable mechanical properties of the hydrogels. d The photographs demonstrating that the hydrogel (5% di-tyrosine crosslinking degree) can repeatedly switch between rigid (20 °C) and soft state (50 °C). Scale bar, 20 mm. Data in (a) and (d) are representative of n = 2 independent experiments. Data in (b) are presented as mean ± s.d. of n = 3 independent samples, and are representative of two independent experiments. Source data are provided as a Source Data file.
