Bio‐solar cells have been studied as sustainable and biocompatible energy sources with significant potential for biomedical applications. However, they are composed of light‐harvesting biomolecules with narrow absorption wavelengths and weak transient photocurrent generation. In this study, a nanobiohybrid‐based bio‐solar cell composed of bacteriorhodopsin, chlorophyllin, and Ni/TiO2 nanoparticles is developed for the first time to overcome the current limitations and verify the possibility of biomedical applications. Bacteriorhodopsin and chlorophyllin are introduced as light‐harvesting biomolecules to broaden the absorption wavelength. As a photocatalyst, Ni/TiO2 nanoparticles are introduced to generate a photocurrent and amplify the photocurrent generated by the biomolecules. The developed bio‐solar cell absorbed a broad range of visible wavelengths and generated an amplified stationary photocurrent density (152.6 nA/cm2) with a long lifetime (up to 1 month). Besides, the electrophysiological signals of muscle cells at neuromuscular junctions are precisely regulated by motor neurons excited by the photocurrent of the bio‐solar cell, indicating that the bio‐solar cell can control living cells by signal transmission through other types of living cells. The proposed nanobiohybrid‐based bio‐solar cell can be used as a sustainable and biocompatible energy source for the development of wearable and implantable biodevices and bioelectronic medicines for humans.This article is protected by copyright. All rights reserved