A D V A N C E D M A T E R I A L S & P R O C E S S E S | A P R I L 2 0 2 2 7 PROCESS TECHNOLOGY SELF-ASSEMBLING MATERIAL A new, scalable material that is stronger than steel and as light as plastic was developed by scientists at MIT, Cambridge, Mass., using a novel polymerization process. The new material is a 2D polymer that self-assembles into sheets, unlike all other polymers, which form one-dimensional, spaghetti-like chains. Until now, scientists believed it was impossible to induce polymers to form 2D sheets. Such a material could be used as a lightweight, durable coating for car parts or cell phones, or as a building material for bridges or other structures. The researchers have filed for two patents on the process they used to generate the material. For the monomer building blocks, they use melamine, which contains a ring of carbon and nitrogen atoms. Under the right conditions, these mon- omers can grow in two dimensions, tiny magnets embedded in it. The new “elastomagnetic” material takes advantage of a phase shift to greatly amplify the amount of energy the material can release or absorb. To do this, scientists must engineer a new structure at the molecular or even atomic level. However, this is challenging to do and even more difficult to do in a predictable way. According to the team, by using metamaterials, they were able to overcome those challenges. They not only made new materials but also developed the design algorithms that allow these materials to be programmed with specific responses, making them predictable. This research has applications in any scenario where either highforce impacts or ultrafast responses are needed. umass.edu. This new two-dimensional polymer self-assembles into sheets and could be used as a lightweight, durable coating for car parts or cell phones, or as a building material. Courtesy Christine Daniloff/MIT. forming disks. These disks stack on top of each other, held together by hydrogen bonds between the layers, which make the structure very stable and strong. Because the material self-assembles in solution, it can be made in large quantities by simply increasing the quantity of the starting materials. The researchers showed that they could coat surfaces with films of the material, which they call 2DPA-1. The researchers found that the new material’s elastic modulus is between four and six times greater than that of bulletproof glass. They also found that its yield strength is twice that of steel, even though the material has only about one-sixth the density. mit.edu. PROGRAMMABLE METAMATERIAL Using metamaterials, a research team from the University of Massachusetts Amherst engineered a new rubber-like solid substance that has surprising qualities—it’s programmable, and it can absorb and release very large quantities of energy. As such, this new material holds great promise for a very wide array of applications, from enabling robots to have more power without using additional energy, to new helmets and protective materials that can dissipate energy much more quickly. This new metamaterial combines an elastic, rubber-like substance with BRIEF Two cutting tool and gear tool providers, Star SU of Hoffman Estates, Ill., and Louis Bélet of Switzerland, formed a strategic partnership aimed to enhance each company’s product offerings and expand their combined reach within the Americas and Europe. star-su.com, www.louisbelet.ch. This elastic material is embedded with magnets whose poles are color-coded red and blue. Orienting the magnets in different directions changes the metamaterial’s response. Courtesy of UMass Amherst.
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