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. 2019 Oct 7;116(43):21438–21444. doi: 10.1073/pnas.1911021116

Fig. 2.

Fig. 2.

Material properties of LM–LCE composites. (A) Representative stress versus strain for LCEs and LM–LCE composites; (B) strain limit at break and (C) tensile modulus. Error bars represent SD for ≥ 3 measurements. (D) Representative storage modulus versus temperature for filled and unfilled materials. (E) Representative normalized length change versus temperature during cooling for filled and unfilled materials with a 20-kPa applied load. (F) Thermal conductivity versus volume fraction for unstretched materials for n ≥ 300 measurements with at least 3 samples tested for each volume fraction (blue circles), and for stretched unfilled LCE and 50 vol % LM–LCE, deformed to about 60% elongation (n ≥ 100, orange circles). Error bars represent SDs. The dashed traces represent the theoretical predictions using the Bruggeman effective medium theory formulation (blue) and a modified Bruggeman effective medium formulation for elongated inclusions (orange) (21, 23). (G and H) Histograms of thermal conductivity along the direction of strain (at 60% strain) for a 50 vol % LM–LCE composite and an unfilled LCE; (I) IR heat map showing heat dissipation of a 50 vol % LM–LCE composite and an unfilled LCE after initial heating. The temperature scale ranges from 20 °C (blue) to 120 °C (orange). (J) Normalized change in electrical resistance, R, versus strain of a conductive LM–LCE strip with the red line representing the average and the shaded region representing the SD for 3 samples tested 3 times each (n = 9) with a comparison to predictions from Ohm’s law (dashed curve). (K) Photographs of autonomous self-reconfiguring electrical conductivity upon puncturing through the traces.