Fig. 4: Layer-by-layer fabrication of SHIS sensor and its sensing and self-healing performance.

a Schematic of the five-layer sensor and the composition of each layer. b Layer-by-layer fabrication procedure for the sensor. c Photographs of the three-dimensional printable electrode conductor (SE:EGaIn:SFP = 1:2:2) in various shapes. Scale bar: 0.5 cm. d Conductivity of the electrodes self-healing at −20 °C. The electrodes were subjected to damage and self-healing at −20 °C for five times. Statistical significance of ice nucleation temperature and adhesion strength were assessed using t tests, with a predefined level of significance (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001) (The control group in t test was the original conductivity). e Electrical healing efficiency of the electrode under five cycles of damage–healing process at −20 °C. Error bars: standard deviation (n = 3). f Stress response of the SHIS sensor. g Photographs of SHIS damaged and healed at room temperature for 24 h. h Sensitivity of SHIS before and after self-healing at room temperature. i Sensitivity of SHIS that were self-healed or placed at −20 °C for 10 days.