According to the University of Wyoming, Daniel Rau, assistant professor of mechanical engineering, is advancing soft material 3D printing thanks to a grant from the National Science Foundation (NSF). The grant aims to help new university faculty kick-start their research programs – namely Rau’s Additive Manufacturing Lab (RAM Lab) – by funding research expenses and student stipends.

Rau, who joined the University of Wyoming’s Department of Mechanical Engineering in fall 2024, will use his $198,932 award to study why current AM processes produce ‘warped blobs’ rather than stable, functional products when attempting to print elastomers. His research project is titled “Improving the Vat Photopolymerization 3D Printing of Soft Elastomers Through a Deeper Understanding of Process Dynamics.”

“This particular additive manufacturing process deals with a really unique class of materials called photopolymers. They’re liquid; you hit them with UV light – think of really strong sunlight – and they solidify,” said Daniel Rau. “But we have a lot of questions on how that exact transition from liquid to solid occurs. Our materials are very soft, and we think there are some unique things going on, so we’re making measurements to look at that.”

Understanding the printing process better will require the employment of two novel approaches – photorheology and X-ray photon correlation spectroscopy (XPCS) – to study the adhesion process during curing of the photopolymers on a much deeper level. For the latter experimental process, Rau is collaborating with a team at the Brookhaven National Laboratory on Long Island, New York. Rau will use Brookhaven’s 2.5-kilometer synchrotron to accelerate X-ray beams onto printed materials to get a very localized understanding of what is happening during the curing process.

With the insights gained from these experiments, Rau intends to produce a ‘cookbook’ of sorts, with recipes to help tailor manufacturing processes for soft materials. Successfully mobilizing this technology could have a huge impact on daily living, especially in the biomedical industry.

“There’s a lot of potential. You know, the human body is very soft. So, there are a lot of things the human body likes soft, whether it’s implants or wearable devices,” said Rau. “Or, say you want a more comfortable pair of running shoes. Say you want a better football helmet that can protect against concussions. With 3D printing, we can create these really cool geometries and trusses so that, actually, the geometry absorbs some of the impacts. Between what’s enabled by the 3D printing and what’s enabled by the material, we think we could get really, really good performance. So that’s where I think the transformative potential comes in.”