Fig. 2. Materials, design features.

(A) Schematic illustration of a bioresorbable module. (B) S₁₁ values of the Rx coils with different diameters (d_coil). (C) Example output waveform (red; d_coil = 12 mm) wirelessly generated by an alternating current (black; ~3 V_pp; 13.56 MHz) applied to the Tx coil. (D) Output voltage of devices as a function of tensile strain (left) and twist angle (right) at a fixed transmitting voltage (4 V_pp) and frequency (13.56 MHz). (E) Drug release behaviors of steroid eluting patches with three different ratios of base polymer. (F) Measurements of output voltages of a bioresorbable module (red square, 10 μm thick Mo) and a reference module (black circle, W/Mg with 700 nm / 50 μm thickness) immersed in PBS (37 °C). (G) Schematic illustration of a skin-interfaced cardiac module. (H) System block diagram of the cardiac module. PMIC, power management integrated circuit. (I-L) Comparisons of ECG, HR, respiratory rate, and SpO₂ level determined by the skin-interfaced modules (red; I, J, cardiac; K, respiratory; L, hemodynamic) and a reference device (black). In L, healthy subject holds breath for 60 s (yellow background).