Fig. 1 DC coupon for cyclic bend fatigue test (units are in millimeters) More

Fig. 2 Cyclic bend fatigue test setup. The sample was bent around the mandrel and the carrier paper was bent around the set of rollers. More

Fig. 3 ( a ) Cross section and ( b ) top-down view of RF transmission line configuration 1 More

Fig. 4 ( a ) Cross section and ( b ) top-down view of RF transmission line configuration 2 More

Fig. 5 Uni-axial stretching of printed stretchable silver trace, liquid metal conductor, and theoretical model based on the ideal conductor. Extension rate was 0.1 mm/s. More

Fig. 6 SEM micrographs of silver trace ( a ) before and ( b ) after stretching up to the strain of 150% and SEM micrographs of liquid metal ( c ) before and ( d ) after stretching up to the strain of 250% More

Fig. 7 ( a ) Viscoelastic behavior of the TPU substrate and ( b )change in electrical resistance of liquid metal conductor during the first cycle of loading and unloading at the extension rate of 5 mm/s More

Fig. 8 The change in electrical resistance during cyclic tension fatigue at the extension rate of 5 mm/s and strain amplitude of ( a ) 30%, ( b ) 50%, and ( c ) 100% More

Fig. 9 Recovery of resistance upon unloading after 8000 stretching cycles at strain amplitude of ( a ) 30%, ( b ) 50%, and ( c ) 100% More

Fig. 10 The change in electrical resistance during cyclic bend fatigue for 1000 bend cycles and rate of 1 Hz at bending radius of 2.5 mm for ( a ) sensor 1 and ( b ) sensor 2 of the test coupon More

Fig. 11 Simulation of electromagnetic structure of configuration 1 based on finite element method showing tetrahedral meshes More

Fig. 12 Configuration 1 ( a ) HFSS model bird's eye view, ( b ) top-down view, and ( c ) modeled HFSS results versus VNA measured data More

Fig. 13 Configuration 2 ( a ) HFSS model bird's eye view, ( b ) top-down view, and ( c ) modeled HFSS results versus VNA measured data More

Fig. 14 Illustration of the de-embedding operation More

Fig. 15 ( a ) RF test coupon configuration 1, ( b ) the coupon under tensile U-bend, and ( c )90 deg twist test More

Fig. 16 De-embedded data for configuration 1 before and after 45 deg twist and U-bend test More

Fig. 17 Attenuation constant and phase constant for transmission line configuration 1 before and after 45-deg twist tests More

Fig. 18 RF test coupon configuration 2 at ( a ) 0% strain amplitude and ( b ) subjected to 100% strain amplitude More