Fig. 2: Design and characterization of strain-isolation systems.

A An illustration of a single-unit design of an electrode integrated into the kirigami-patterned adhesive layer. B A detailed scale of the unit cell of the biaxial kirigami pattern. C Deformation results of a kirigami pattern at 10 percent biaxial strain, showing elongation accompanied by rotation at the ends of the perforated lines. Scale bar: 2 mm. D A multi-electrode patch design with perforations at both ends. E Contour map of strain at the midpoint of the patch where the electrode is located, determined by the factors δ and L in the biaxial pattern. F Strain distribution outcomes across different parts of the patch, visualized through DIC. Scale bar: 5 mm. G Comparison results between theoretically predicted strain and experimentally measured values at the center of the patch, along with the strain reduction ratio. Data are presented as mean values with the standard deviation of the mean of 5 experimental values each. H FEA results showing the maximum biaxial strain on the electrode integrated into the patch. I Experimental results showing the measured electrical resistance of the electrode under cyclic loading of 30% biaxial strain, showing negligible changes. J Comparison photos of a plain patch (left) and a kirigami patch (right) designed to prevent buckling delamination. The plain one shows delamination at the electrode location, whereas the kirigami one maintains the surface conformal contact. Scale bar: 5 mm. Measured impedance changes at the digastric muscle during mouth closing (blue points) and opening (red points) motions, without kirigami (K) and with kirigami (L) patterns applied to the patch, respectively.