Researchers have developed micro‑ and nanoscale reconfigurable robots that capture and release carbon dioxide in confined life‑support systems such as crewed spacecraft, submarines, and sealed shelters. The team led by Prof. Hui He at Guangxi University reports that these micro‑nano reconfigurable robots (MNRM) use sunlight as an energy source while moving through the system to avoid local overheating. In tests, the robots captured 6.19 mmol of CO₂ per gram of sorbent and released the gas again at a regeneration temperature of only 55 °C. In a sealed mouse‑chamber experiment, use of the robots extended animal survival time by 54.61 %, indicating their potential to manage carbon levels in extreme environments.

The MNRM design combines several functional components:

• CO₂‑binding molecular groups – form carbamic acid and ammonium bicarbonate when exposed to CO₂.

• Temperature‑responsive molecular switch – based on Pluronic F127 cross‑linked with cellulose nanofibers; it changes configuration in the 45–55 °C range, altering the local electrostatic environment around amino groups on the sorbent. This weakens nucleophilic attack on adsorbed intermediates and suppresses side reactions that would form difficult‑to‑regenerate urea structures.

• Solar photothermal conversion layer – enables operation under solar irradiation as low as 0.7 sun (≈ 700 W m⁻²).

• Magnetically driven motion elements – Fe₃O₄ nanoparticles embedded in the robots provide remote, non‑contact control of motion and orientation. Under an applied magnetic field, MNRM particles move collectively in a “school‑of‑fish” pattern, distributing them uniformly through the fluid and ensuring even light exposure and heat distribution. A graphene‑oxide layer acts as a heat bridge, spreading photothermal energy through the three‑dimensional framework and preventing hot spots that could damage the sorbent or surrounding components.

Performance results

• After ten hydrothermal regeneration cycles at 55 °C, the robots retained 94 % of their CO₂‑capture capacity.

• After ten cycles under 0.7 sun illumination, they retained 91.6 % capacity.

• The materials exhibited antimicrobial effects, inhibiting > 98 % of Escherichia coli, Staphylococcus aureus, and Aspergillus flavus growth—relevant for long‑term storage and operation in life‑support systems.

• In life‑support simulations, the robots kept CO₂ concentrations in the test chamber below 2 % and preserved mouse lung tissue at grade 1, indicating limited damage.

The research team is now working on integrating the MNRM materials into modular cartridge formats that could fit into extravehicular‑activity backpacks and compact life‑support loops for small submarines or emergency shelters.

Research report: Micro/Nano‑Reconfigurable Robots for Intelligent Carbon Management in Confined‑Space Life‑Support Systems.