Kirigami-Patterned Highly Stable and Strain Insensitive Sweat pH and Temperature Sensors for Long-term Wearable Applications

Strain-insensitive wearable sensors have garnered substantial attention owing to their high precision sensing irrespective of body movements such as bending, stretching, and twisting motions. This work reports integrated, strain-insensitive pH and temperature sensors fabricated on a biaxially stretchable kirigami structure to quantitively measure the sweat pH levels and body temperature. Notably, an impressive strain-invariant response was demonstrated by the pH and temperature sensors under an applied biaxial tensile strain up to 220% and torsional strain up to 360°. By depicting an excellent combination of cost-effective fabrication, flexible kirigami structure, breathable notches, high linearity of response, and skin conformity, our device will open a promising new route in the application of skin-inspired wearable sensors.