Overview of the design principle of the SOS. (a) Abstract diagram showing the SOS for regulating glucose homeostasis in diabetic mice. (b) Diagram showing the components of the SOS. The i-PENG converts biomechanical energy from murine respiration movement into electricity to provide energy to the power management unit that powers the LED. The PMU consists of three modules: a rectifier bridge, a button cell, and a magnetic switch. (c) Mechanism of FRL-inducible transgene expression in engineered human HEK-293 cells. (d) 3D structure of the i-PENG. The i-PENG consists of the poly (vinylidene fluoride) (PVDF) film, electrodes (Ag), and a substrate layer (polyimide, PI), which were encapsulated by biocompatible materials (polyethylene terephthalate (PET) and parylene-C). (e) The operating mechanism of the i-PENG.