Mechanical Metamaterials in nature (Magazine)

Mechanical metamaterials achieve properties not found in nature through engineered architecture on a mesoscale. Mesoscale refers to an intermediate scale, between the larger scale of parts and loading forces, and the smaller scale of a materials microstrucutre. As engineers and researchers, we ask the question: if you could design foams and choose the shape of bubbles, what would you pick? The answer will depend on the properties you are looking for, of course.

In 1963 a theoretical upper bound was developed by mathematicians that governs the specific stiffness of foams. Foams are material systems characterized by having arrays of voids (bubbles) embedded in a soft or hard matrix. Many studies use this bound as a performance metric and the paper has been cited more than 7000 times. There have been many attempts to design material systems that achieve this upper limit. Foams see ubiquitous use in engineered systems but historically are made up of quasi-random arrays of bubbles. Now we can 3-D print a new class of foams and the question is: what to print?

In 2014, Nama Development scientist, Dr. Jonathan Berger, engineered the first single length scale design capable of achieving this upper limit (check out our paper featured in Nature). Single length scale means that it can be 3-D printed. Previous designs had been largely theoretical as they required features on multiple length scales, meaning that they required that some features be much smaller than others, making them difficult if not impossible to fabricate. Dubbed Isomax™, this patented design provides maximum material efficiency.

Using Isomax™ makes the best use of material possible, achieving maximum performance in terms of stiffness and strength per gram (check out another paper we published in Nature). In a world where energy use and material consumption should be on most people’s minds, Isomax™ provides performance where it matters.

Soft materials are perhaps one of the most interesting applications. 3-D printing in many forms requires a stiff and stable structure below to deposit material on top of. Isomax™ provides the stiffest structure possible to achieve the lightest and lowest density designs possible.

As a materials company, we are always looking for subject matter design experts looking to use our metamaterial designs. If you are interested, please reach out to us. We would love to hear from you.