From nuts and bolts to smart metals: New 3D-printed shape memory alloys can redefine engineering
Researchers have developed active interlocking metasurfaces (ILMs) using shape memory alloys (SMAs) like Nickel-Titanium (NiTi), which are metals that can "remember" and return to their original shape when heated. These new ILMs can lock and unlock based on temperature, making it a smarter way to create mechanical connections between materials.
Traditionally, joints and fasteners like bolts or adhesives are used to hold components together. However, ILMs use tiny interlocking features to connect parts, allowing them to transmit force and limit movement in precise directions. You might be wondering where the innovation lies in all of this? It lies in adding active materials like NiTi, which change shape when heated, to make these joints more responsive. These joints allow for controlled engagement and disengagement of the surfaces, without the need for manual intervention or external force.
The study explored two different ILM designs, called Pinch Grip (PG) and Expanding Anchors (EA). These were built using a technique called additive manufacturing, which is similar to 3D printing but for metals. By heating these structures, the researchers could activate the shape memory effect (SME), allowing the parts to move, lock, or unlock as needed. This makes the joints adaptable and ideal for dynamic environments, where components may need to be frequently reassembled or adjusted.
Using computer modeling (finite element analysis), the team was able to predict how these ILMs would behave under stress, and thermomechanical testing showed they could withstand repeated use without losing their strength or shape recovery ability.
This study is a major showcase of how combining advanced materials and additive manufacturing can lead to new ways of creating strong, flexible, and smart connections for engineering and industrial applications.
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