Micro nano robots aim to cut carbon buildup in closed life support systems

by Riko Seibo
Tokyo, Japan (SPX) Dec 03, 2025

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, or 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 degrees Celsius. In a sealed mouse chamber experiment, use of the robots extended animal survival time by 54.61 percent, indicating their potential to manage carbon levels in extreme environments.

The MNRM design combines several functional components: CO2 binding molecular groups, a temperature responsive molecular switch, a solar photothermal conversion layer, and magnetically driven motion elements. The CO2 binding moieties form carbamic acid and ammonium bicarbonate when exposed to carbon dioxide. A molecular switch based on Pluronic F127 cross linked with cellulose nanofibers changes configuration in the 45 to 55 degree Celsius range, which alters the local electrostatic environment around amino groups on the sorbent. This change weakens the nucleophilic attack capability of the amino groups toward adsorbed intermediates, suppressing side reactions that would form urea structures that are difficult to regenerate.

By limiting urea formation, the nano reconfiguration lowers the energy barrier for CO2 desorption and allows regeneration at 55 degrees Celsius, at least 25 degrees lower than other amino based sorbents reported so far. The lower temperature translates to an estimated one third reduction in thermal energy required for regeneration. The robots achieve this while operating under solar irradiation as low as 0.7 sun, or about 700 watts per square meter, which supports use in resource constrained habitats.

Magnetic Fe3O4 nanoparticles embedded in the robots provide remote, non contact control of their motion and orientation. Under an applied magnetic field, MNRM particles move collectively in a school of fish like pattern, which distributes them through the fluid and supports uniform light exposure and heat distribution. A graphene oxide layer acts as a heat bridge, spreading photothermal energy through the three dimensional framework and helping to prevent hot spots that could damage the sorbent or surrounding components.

In performance tests, the robots maintained 94 percent of their CO2 capture capacity after ten hydrothermal regeneration cycles at 55 degrees Celsius and 91.6 percent capacity after ten cycles under 0.7 sun illumination. The materials also showed antimicrobial effects, inhibiting more than 98 percent of Escherichia coli, Staphylococcus aureus, and Aspergillus flavus growth, which is relevant for long term storage and operation in life support systems. During life support simulations, the robots kept CO2 concentrations in the test chamber below 2 percent 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