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Engineers have long looked to origami and kirigami for inspiration when designing lightweight structures that can transform shape without relying on complex mechanical systems. While origami uses folding to create three-dimensional forms, kirigami introduces carefully placed cuts that allow flat materials to bend, expand, and deform in unusual ways. However, most engineering applications have focused on simple cut patterns aligned with the direction of force, limiting the range of achievable motions.
Researchers have now developed a new kirigami structure that behaves differently. By introducing angled cuts instead of the traditional parallel or perpendicular patterns, they created a material that twists automatically when stretched, opening new possibilities for soft robotics, medical devices, and adaptive mechanical systems.
According to TechXplore, the design begins as a flat polyester sheet containing a series of precisely spaced laser-cut slits arranged at an incline. After fabrication, the sheet is rolled into a cylindrical shape and subjected to mechanical loading. When tension is applied along the length of the cylinder, the structure does not simply elongate. Instead, it rotates and twists as it stretches.
This behavior is linked to a property known as chirality. A chiral object cannot be superimposed on its mirror image, much like a left hand and a right hand. The angled cut pattern introduces this handedness into the material, allowing it to convert linear pulling forces into rotational motion.
Researchers found that some versions of the structure also exhibit auxetic behavior. Most materials become thinner when stretched. Auxetic materials do the opposite: they expand laterally as they elongate. This unusual characteristic can improve energy absorption, flexibility, and mechanical stability.
The ability to generate twisting motion directly from stretching is particularly interesting for soft robotics. Conventional robotic joints often require motors, gears, or other rigid mechanisms to create rotational movement. The new kirigami structure functions as a passive twist actuator, producing rotational motion through its geometry alone.
From a defense and security perspective, lightweight structures capable of controlled shape change could support deployable systems, adaptive sensors, wearable technologies, and soft robotic platforms designed to operate in confined or unpredictable environments.
The work also highlights a broader trend in materials engineering: using geometry rather than additional components to create new mechanical functions. In this case, a carefully arranged pattern of cuts transforms a simple sheet into a structure capable of converting one type of force into another.
The research was published here.
