Engineered living materials (ELMs) combining microalgal biomass with biopolymeric scaffolds hold promise for sustainable carbon capture and storage, yet their long-term performance and controllability remain underexplored. We report the fabrication and evaluation of a multi-layered fibrous hydrogel incorporating Chlorella vulgaris as the active photosynthetic component. Each sample contained 0.5 g dry algal biomass embedded within a 40 g composite matrix, yielding an effective surface area of ~0.5 m².

Continuous monitoring was conducted over 33 days in sealed environmental chambers (relative humidity 85–99%, 27–29 °C, natural light–dark cycles, no additional culture medium applied). Routine gas analysis using an NDIR CO₂ sensor confirmed sustained photosynthetic uptake. Periodic CO₂ injections (10,000–25,000 ppm) triggered repeatable fixation cycles, with concentrations routinely declining to near-zero (0–100 ppm) during light periods. The integrated uptake corresponded to 89,000 ppm, equivalent to 160.1 g CO₂ captured. Post-experiment destructive sampling revealed a net biomass increase of 0.10 g (total 0.6 g), corresponding to 20% growth. Material viability and photosynthetic activity were preserved for >30 days, demonstrating functional longevity under semi-passive conditions.

The fibrous architecture supports stable immobilization while maintaining gas–liquid exchange, enabling repeatable carbon removal cycles without external aeration. Building on these results, the next stage will introduce femtosecond (fs) laser stimulation as a non-invasive method to modulate enzymatic activity, specifically carbonic anhydrase, with the goal of enhancing carbon fixation rates in situ. This combined approach of advanced biofabrication and ultrafast optical regulation establishes a pathway toward responsive, low-energy living materials for carbon management.