Enhanced and Sustainable Indoor Carbon Dioxide Monitoring by Using Ambient Light to Power Advanced Biological Sensors

Enhancing carbon dioxide (CO 2 ) detection is crucial for improving indoor air quality and environmental surveillance. Traditional CO 2 sensors face drawbacks like high costs, large sizes, environmental impact, and reliance on external power, limiting their practicality for continuous indoor monitoring. In this research, an innovative indoor CO 2 ‐sensing system using a self‐powered bio‐solar cell (BSC) platform is introduced. Utilizing cyanobacteria as a sensitive biocatalyst and sustainable power source, the system offers a cost‐effective, eco‐friendly, and maintenance‐free alternative to conventional sensors. It operates by monitoring electron‐transfer processes in cyanobacteria during photosynthesis, converting CO 2 and water into oxygen and chemical energy, enabling accurate CO 2 level monitoring. The system responds to CO 2 fluctuations and issues alerts when levels are outside the recommended range of 500–1000 ppm for human health and productivity. A self‐sustaining configuration of eight BSCs—one for sensing and others for power generation—ensures continuous operation without external power. An integrated energy‐harvesting board efficiently manages power distribution to a microcontroller and display system for real‐time data visualization, with the array producing up to 400 μW. Additionally, a machine‐learning model interprets BSC outputs to accurately quantify CO 2 levels, enhancing the sensor's adaptive performance.