Ultra-flexible optoelectronic stimulator converts tissue-attenuated weak light into electrical signals for cardiac remodeling.

Precise spatiotemporal resolution and wireless multi-site modulation of excitable tissues via optoelectronics offers transformative potential for bioelectronic medicine, yet clinical translation is hindered by the rigidity of conventional silicon-based devices and their reduced performance under tissue-attenuated illumination, where the weak light reaching implants often fails to generate sufficient stimulation voltage. Here, we report an ultra-flexible, high-efficiency optoelectronic stimulator (OES) based on (Bi,Sb)2Se3, a semiconductor with crystal structure comprising parallel 1D chains that enable efficient flexibility and photocarrier transport. The OES achieves robust photoelectric conversion under near-infrared light intensities as low as 0.55 μW cm-2, reaching quantum efficiency of up to 89.60% while conforming seamlessly to soft tissues. In a rat model of myocardial infarction, the OES restored electrical conduction across infarcted regions and improved cardiac function under weak-light stimulation. Scalable fabrication yields large-area devices without loss of performance, as validated in a swine model. This work introduces a clinically translatable optoelectronic platform for soft-tissue modulation under low-power light, establishing a foundation for next-generation, minimally invasive cardiac repair technologies.