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upstart writes:

Scientists made a wooden knife that's three times sharper than steel blades:

The gold standard for knives is usually steel or ceramics, but in a new study, appearing in the journal Matter on Oct. 20, material scientists describe their latest creation: A "hardened wood knife" around three times sharper than a stainless steel dinner knife. It can "easily" cut through a medium-well done steak, according to Teng Li, a materials scientist at the University of Maryland and first author on the paper, and can be used and reused many times.

[...] Li's team developed a two-step method for hardening the wood in their knives that increased the blade's hardness 23-fold. This was achieved by ensuring the wood retained a higher level of cellulose.

Typically, wood contains only about 50% cellulose, which provides some structural integrity, and weaker molecules make up the rest. Li's two-step process was able to remove these weaker components but retain the cellulose. Coating the wood in mineral oil helps protect its sharpness during use and washing.

[...] They discovered the two-step process the used(sic) prevented defects from creeping in. "The strength of a piece of material is very sensitive to the size and density of defects, like voids, channels, or pits," he said in a statement.

The team didn't stop at hardened wooden knives, either. They also developed wooden nails, showing they were as sharp as conventional steel nails.

Also at ScienceDaily

Journal Reference:
Bo Chen. Hardened wood as a renewable alternative to steel and plastic, Matter [open] (DOI: 10.1016/j.matt.2021.09.020)

Original Submission