A Fabric That Is Still Alive, and Can Be Regrown Where It Tears
Put a drop of nutrient solution on this cloth and, a few days later, fine fuzz has grown exactly where the drop landed. Its makers have written their institute's logo that way, along with snowflakes, honeycombs and leaves. It works because the cloth was never really finished: the fungus it is made of is still alive inside it, and it will still grow if you feed it.
Ke Li, Chao Zhong and colleagues at the Shenzhen Institutes of Advanced Technology, part of the Chinese Academy of Sciences, described the material July 24 in Science Advances. Almost every way of turning fungus into a material kills it: hard drying, heat or chemical cross-linking, all of which buy a fixed shape by removing the living part. This one skips all three. Spores of Cordyceps militaris, a fungus that grows as a mat of fine threads, are shaken in liquid until the threads clump into soft pellets, which are pressed into a mold and dried at 45 °C. They knit into one continuous sheet because the threads grip each other unaided, and nothing gets hot or dry enough to kill the inside.
A sheet like that is brittle, so it is soaked in glycerol, the syrupy alcohol that keeps cake icing soft. Glycerol works between the sugar chains of the fungal wall and loosens the stiff web of bonds holding them in place; a 10% soak left the film about half again as stretchy with no loss of strength, while stronger solutions separated out and left it slack. Glycerol is also thirsty for water, which is the awkward part: the plain sheet is wettable. Whatever sheds water on this fabric, it is not the fabric.
The water runs off the fuzz, not the cloth
It runs off the aerial hyphae, the fine threads the fungus pushes up into the air when it finds food. Wet a patch with nutrient, keep it humid, and the living sheet grows its own felt. On that felt a water droplet stands at about 145 degrees, a steep bead rather than a puddle. Dirty water stayed in spheres and rolled off, leaving next to nothing behind. No coating is involved anywhere; the usual self-cleaning fabric relies on fluorinated chemistry or micro-patterning.
Because the sheet is alive, damage becomes something closer to gardening than to mending. The authors report that they cut holes in their films, packed fresh wet pellets into the gaps, fed the spot and left it damp; the new growth bridged the cut and the repaired area looked like the fabric around it. They did that ten times over on the same piece, and the repellency came back each time at the same steep angle, with most of the original stiffness intact. This is assisted repair, not a self-healing fabric: it takes new pellets, food, damp air and a pair of hands.
The color arrives as a passenger
A living thread network is mostly chitin, the tough sugar that also makes insect shells, and plenty of proteins are built to grab chitin. So the team took the ordinary yeast of bread and beer, Saccharomyces cerevisiae, and hung a chitin-grabbing protein off its surface. It stuck to the fungal threads and stayed stuck: after hours in an ultrasonic bath, about 75% was still attached, against 18% of yeast without the grabber.
Engineered strains of that yeast supply the color, pale blue, red, orange and deep purple, either by converting an added chemical or by building the pigment from scratch, with mixtures covering the range between red and purple. From the blue version the group sewed a dress: self-pigmented panels, a collar of leaf-shaped pieces, a hem of petals furred with aerial hyphae. The color is less dynamic than the fabric: the yeast make their pigment before they go in and are nutritionally hemmed in once inside, so it sets as a property of the material rather than being topped up, dimming a little over two weeks without going washed out.
The ultraviolet module is a second fungus and a blunter step. To grow a melanin-rich skin the sheet is heated to 120 °C, killing the Cordyceps still living in it, then sprayed with spores of Aspergillus niger, the black mold of forgotten fruit, which cover it in a dark layer within days. That layer soaks up ultraviolet light and scavenges free radicals in two standard tests. The shielding was tested biologically: spores on a plate covered by the coated sheet and put under a germicidal lamp germinated almost normally, while uncovered spores largely did not.
Forty-one days, in a tray indoors
At the end of its life the authors buried a small box of the material in loamy, pesticide-free soil from a local farm plot, sieved and kept in trays indoors at 22 to 26 °C and around half humidity. Within 41 days it had nearly all fallen apart. That is disintegration judged by eye, on one small object of one formulation, in soil the authors describe as standing in for indoor or sheltered outdoor conditions, rather than a measurement of how much of its carbon returned to the air.
An accounting of the process from raw materials to dried biomass puts the costs in unglamorous places: preparing the growth medium dominates water use, disposing of spent medium drives the greenhouse-gas and toxicity totals, and glycerol dominates ozone depletion and land use. Raw materials, mostly nutrient media, are more than 95% of what a batch costs.
None of it is offered as clothing. The authors write that the material belongs in short-term or single-use textile-like systems, biodegradable packaging, exhibition pieces and architectural displays, rather than garments meant to last, and that washability, abrasion resistance, breathability and wearer comfort have not been systematically evaluated at all. The dress shows the sheets can be cut and sewn. It is not a product.
The study is published open-access, and the researchers have made all necessary replication data publicly available within the paper and its supplementary materials. Regarding potential conflicts of interest, Chao Zhong is associated with Shenzhen PAM2L Biotechnologies, and he, Ke Li, Xinyu Wang and Bolin An are listed as inventors on an institutional patent application covering the living fungal textile. Additionally, one of the co-authors is affiliated with PEELSPHERE GmbH in Berlin, and the team acknowledged a colleague at the company for assisting with the design and fabrication of the textile dress.