Figure 3
Characterization of the liquid-metal strain gauge. (a) Optical images of the strain sensor before and after stretching by 30%. (b) Measured (solid line) and computed (dotted line) variation of the resistance. (ΔR) with strain for sensors with various widths. (c) Measured (solid line) and computed (dotted line) variation of the normalized change in the resistance (ΔR/R0) with strain. (d) Reversible loading-unloading behavior for various peak strains at a strain-loading rate of 0.5 mm s−1. (e) Reproducible change in resistance for repeated stretching cycles. (f) Change in resistance as a function of time for repeated strain loading (to 30%) and unloading for 10 000 cycles. The inset shows an enlarged view of the specific time interval highlighted as a yellow rectangular box. (g) Illustration of a setup for the measurements of resistance as a function of normal force (applied pressure). (h) Normalized change in resistance as a function of applied pressure. (i) Reproducible change in resistance for repeated cycles of pressure loading.
