Shape Morphing Domes

I spent the summer of 2025 at Imperial College London, working in the MaXtaloy Group in the Department of Materials.

My goal was to create an environmentally sensitive structure that changes shape with response to an external cue. I was particularly interested in starting from a flat sheet, and creating height.

The hope is to scale these structures, and utilize their minimal profile state prior to deployment as a means of creating habitable structures in extreme environments.

Material Choice

Design

I created the designs through Grasshopper in Rhino, allowing me to easily change parameters and generate new variations. With the many materials I prototyped with (paper, card, stainless steel, aluminum and nitinol) I focused on the main attributes that change the ease of deploying the structures (i.e, the pressure required to deform into a dome). Three attributes control this factor: number of rings, the number of divisions of each ring, and the length of each arc division.

Given the superelasticity of nitinol, and the thickness of the sheet provided, the nitinol design was chosen to have high ring number, low division number and high arc length. This makes each “segment” of the dome thin and long, and consequently easy to deform.

Prototyping

I prototyped the domes out of card, stainless steel and aluminum. The cuts were made using a universal laser cutter and a Rofin laser cutter. I also CNC milled an aluminum model, but ultimately decided against that manufacturing method because of the endmill’s role in removing material and limiting the dimensions of the dome segments.

I test cut strips of Nitinol on the Rofin, to ensure that the heat of the laser didn’t vaporize off too much nickel and affect the shape memory properties of the dome. I then optimized the Nitinol design before cutting it, and moving on to heat training.

Number of Rings

Length of Divisions

Number of Divisons

Training

Manually deforming the sheet into a dome and then heating it causes it to collapse. To train it to rise when heated, the dome must be deformed and braced, then heated over its phase transition temperature into the austenite phase, before being quenched. The quenched structure can then be manually flattened into a sheet and heated again to rise into the dome.