These 3D Printed Biocatalytic Fibers Scrub Carbon Dioxide

On today’s episode of “What If?” — what if the Apollo 13 astronauts had a 3D printer? Well, for one thing, they may have been able to avoid all the futzing with duct tape and procedure list covers to jury rig the lithium hydroxide filters, at least if they’d known about these 3D printed enzymatic CO2 filters. And time travel…they probably would have needed that too.

Yes, it is a stretch but CO2 Scrubbing is one of the uses for what [Jialong Shen] et all The Textile Engineering Department of North Carolina State University has developed this. The star of the show isn’t so much the 3D printing — although squirting out a bio-compatible aerogel and cross-linking it with UV light on the fly is pretty cool. CO2-scrubbing textile is carbonic anhydrase, or CA, a ubiquitous enzyme that’s central to maintaining acid-base homeostasis. CA is a small enzyme that catalyzes water’s addition to carbon dioxide, resulting in bicarbonate and hydrogen. CA can convert up to 1,000,000 CO molecules into bicarbonate and hydrogen ions.2 CO emits a high number of molecules per second. This makes it a very attractive CO2 filter.

In the current work, an aerogel of poly(ethylene glycol) diacrylate/poly(ethylene oxide) (PEG-DA/EO) was used to entrap CA molecules, holding them in place in a polymer matrix to protect them from denaturation while still allowing access to gaseous CO2. The unlinked polymers are mixed with photoinitiators in a solution of Carbonic Anhydrase, and then extruded with a fine nozzle using a syringe. The resulting thread was blasted with 280–450 nm UV light, curing the thread instantly. The thread can be wound as a monofilament to later weave or directly printed into a grid.

The filament performed well at CO2 Capture, able to scavenge 24 % of the gas from mixtures passed over it. What’s more, the entrapped enzyme appears to be quite stable, surviving washes with various solvents and physical disruptions like twisting and bending. It’s an exciting development in catalytic textiles, and besides its obvious environmental uses, something like this could make cheap, industrial-scale bioreactors easier to build and run.

Photo Credits: [Sen Zhang] The following are some examples of how to get started: [Jialong Shen]NC State University [Rachel Boyd], Spectrum News 1