Think of a sandwich. In many cases, thicker is better. But in the manufacturing space, which commonly uses layered “sandwich” materials, thin and lightweight structures are better. 

A research team at Southern Illinois University Carbondale is trying to make sandwich materials in a more energy-efficient manner. The National Science Foundation granted SIU assistant professor Sabrina Nilufar $200,000 for a two-year study on how to save energy, time, and money while more easily creating sandwich materials through additive manufacturing, or 3D printing.

What are these sandwiches?

Sandwich structures typically consist of two thin outer material sheets that surround a lightweight core material. They’re used in a variety of applications where material weight and strength are important, such as aerospace, automotive, and thermal insulation.

The core layer’s geometry significantly influences the structure’s overall performance. Yet engineers face challenges with improving the core structures or developing new ones because of manufacturing process limitations.

Manipulating manufacturing methods

Conventional sandwich structure manufacturing tends to be wasteful because of the amount of excess materials that are unused in the final product. Additive manufacturing offers a customized, more precise fabrication method with little waste material because it “prints” an object one layer at a time.

3D printing’s precision provides a more energy-efficient and cost-effective process than conventional manufacturing. Some engineers believe parts produced this way are also higher quality. The targeted method is feasible for producing rarely needed or discontinued parts.

Nilufar’s team is combining additive manufacturing principles with triply periodic minimal surface architecture, which uses complex geometries to improve material strength and weight ratios and could simplify fabrication. She aims to figure out how TPMS architecture improves the mechanical and thermal properties of sandwich core materials.

Her team also will develop 3D models that predict these properties. They will examine how to optimize material characteristics including size and thickness and determine how TPMS structures perform under various loads and temperatures.

“We hope the project helps us gain new understandings of how these forces would impact TPMS structures in the real world,” Nilufar said in a news release.

The researchers expect this project to help refine new manufacturing processes for sandwich materials that consume less energy, produce less waste, and are more economically beneficial.