This project is based on a single unit that exhibits bistability — meaning it can stably maintain two distinct states (like an ON/OFF switch) without continuous external energy. The unit consists of a hollow rectangular base connected to a sinusoidal arch. When the arch is "snapped" to its second stable state, the base curves significantly, enabling the unit's morphing capability.

First stable state of the bistable arch unit

First stable state (Unsnapped)

Second stable state of the bistable arch unit

Second stable state (Snapped)

By concatenating these bistable units, we created 1D arrays capable of complex shape-shifting, where the final configuration is determined by the specific combination of snapped units.

A three-unit array demonstrating different morphed shapes.

Here are two timelapses of the array for two different snapping sequences. The end result is a C shape.

Undeformed S-shape array

Sequene: 1, 2, 3

Morphed S-shape array

Sequene: 2, 3, 1

We further demonstrated the array's programmability by designing structures capable of achieving complex, such as the 'M' and 'S' configurations:

Undeformed M-shape array

M-shape: Undeformed

Morphed M-shape array

M-shape: Morphed

Undeformed S-shape array

S-shape: Undeformed

Morphed S-shape array

S-shape: Morphed

The complete work, including numerical modeling and experimental validation, is published here: https://doi.org/10.1016/j.ijsolstr.2024.112917