Fig. 4. Computational modeling results and sensor’s long-term stability and reliability.

(A) Bending stability simulation showing the minimum bending radius of a sensor’s film according to the covered PI thickness. (B) Maximum stretching simulation of a stretchable serpentine line for each sensor’s design. (C) Surface plot based on minimum bending radii at a given combination of variable membrane thicknesses for three sensors. No film damage at any combination under 10-mm radius is observed over 55,000 bending cycles. (D) Schematic illustration of the bioreactor setup to identify long-term sensor reliability with a rocking condition of the bioreactor. The rocking bioreactor is located inside the incubator for up to 30 days. (E) Signal strength from the sensor during 7 days of the rocking process, showing the received signal strength indicator (RSSI) and data transfer rate (BTR) at a 5 m distance between the system and the mobile device. (F) Reliability of the thin-film pH, temperature, DO, and glucose sensors, evaluated until 30 days under continuous system rocking. All sensors maintain long-term robustness within 1% of performance variation for 30 days.