Figure 3. Characterization of the stretchable wideband antenna under large deformations or attached to human bodies.

(A) Optical images of the stretchable wideband dipole antenna upon deformation (i.e., stretching, bending, and twisting). (B) Simulated strain distributions in the Ecoflex substrate and Ag/LIG layer of the stretchable wideband antenna upon bending and twisting deformations. (C) Measured S₁₁ curves of the stretchable dipole antenna upon bending or twisting. (D) Simulated S₁₁ curves of the stretchable wideband antenna attached above human wrists at various distances from 1 to 5 mm. When attached to human bodies, the “double-peak” characteristic of the stretchable dipole antenna disappears due to a high dielectric constant of human bodies. The double resonance gradually recovers at a distance of 4 mm. (E) Optical images of the stretchable wideband antenna placed on different parts of human bodies, including the arm, head, abdomen, or a nylon jacket, with (F) the corresponding measured S₁₁ curves.