[Reading Science] Is There 3D Printing and Biodegradable 'Danbaekjil Yuli'?

Chinese Academy of Sciences Published Paper on 17th Last Month
3D Printing and Mold Processing Possible Using Protein
Acid Resistance and Biodegradable, No Waste Disposal Concerns

Glass is currently one of the most widely used materials by humanity. It is made by mixing quartz silicon (硅砂) with sodium carbonate and limestone. Transparent, it allows light to pass through directly, and it is hard and highly acid-resistant, making it indispensable in architecture, industry, and everyday household items. However, it is brittle and breaks easily. It is difficult to process into desired shapes. Waste disposal and recycling also require considerable effort. Scientists have addressed these drawbacks by creating glass using proteins as materials. Through 3D printing and molding, its shape can be freely altered. It naturally decomposes, making disposal clean and easy. However, it melts quickly, making it unsuitable for storing beverages or alcohol.

A research team from the Institute of Process Engineering at the Chinese Academy of Sciences (CSA) published these findings on the 17th of last month in the international academic journal Science Advances. Conventional glass is made from inorganic molecules such as silicon dioxide. These components melt at high temperatures and cool quickly. Glass waste is relatively easy to recycle, but a significant amount is landfilled and takes thousands of years to decompose.

Glass bottle. Stock photo. Not related to the article.

In contrast, amino acids are easily broken down by microorganisms. Glass made from amino acids naturally decomposes and is absorbed into the soil ecosystem within a few years, even if landfilled as waste. The problem is that amino acid compounds (peptides and proteins) tend to disintegrate before melting when heated. The research team found a way to prevent this early decomposition by modifying the terminal ends of amino acids and changing their bonding methods. They then melted the modified amino acids and rapidly supercooled them to maintain the molecular arrangement in a liquid state. Subsequent cooling solidified the amino acid melt, vitrifying it into glass.

This glass remained solid even when returned to room temperature. This method prevented the formation of crystalline structures during solidification, resulting in a transparent property. The glass produced in this way also exhibited consistent acid and alkali resistance. It was confirmed to withstand exposure to digestive fluids and compost for several weeks to months.

Su Ting, a professor of materials engineering at the University of California, USA, commented, "Although this research is still at the laboratory stage, it opens a new path for those studying materials. Protein-based glass is expected to be less hard than conventional standard glass. However, this property could be advantageous for small and flexible devices such as lenses and microscopes."