For most of us, knitting brings to mind sweaters, scarves, and perhaps an ambitious grandmother determined to make winter more fashionable. Researchers at Harvard University, however, have a far more futuristic vision. They’ve transformed ordinary knitted fabric into a programmable material capable of changing shape, acting as an electrical switch, sensing movement, and potentially forming the foundation of tomorrow’s wearable technology.

The research, published in Advanced Functional Materials by scientists at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), demonstrates how machine-knitted textiles can “snap” between multiple stable shapes without relying on motors or rigid mechanical parts.

In simple terms, these fabrics behave less like clothing and more like soft robots.

A knitted fabric that remembers its shape

The breakthrough revolves around a concept known as multistability, where an object can naturally settle into more than one stable configuration. Think of a light switch. It doesn’t stay halfway between on and off. Instead, it snaps cleanly into one of two positions.

The Harvard team managed to recreate that behaviour using nothing more than specially selected elastic yarns and industrial knitting techniques. Led by Kausalya Mahadevan, now a postdoctoral researcher in Professor Katia Bertoldi’s lab, the project combines principles of textile engineering with nonlinear mechanics, an area of physics that studies how materials bend, buckle, and snap under force.

Instead of moulding plastics or engineering complex polymers, the researchers relied on weft knitting, the same manufacturing process used to produce everyday garments like hats, gloves, and sweaters. By carefully arranging different elastic yarns using a technique called plating, they created dense knitted structures that naturally curl into three-dimensional forms.

The result is a textile that can repeatedly change shape while reliably returning to predefined positions.

From smart clothing to programmable interiors

The team didn’t stop at creating shape-shifting fabric. To demonstrate practical applications, researchers integrated conductive yarns into the textile, allowing it to function as a soft electrical switch. One prototype turned an LED on and off simply by snapping between two stable positions.

Another transformed the fabric into a wearable motion sensor. Mounted over a person’s knee or elbow, the textile detected each snap and transmitted the motion to an Arduino controller that could count steps. Perhaps the most eye-catching demonstration was a reconfigurable lampshade. By stretching different parts of the knitted structure, users could activate separate switches that changed the lamp’s colour, all without traditional buttons or electronics dominating the design.

One of the biggest advantages is scalability. The researchers developed these textiles using machines already found in commercial garment factories, meaning the technology doesn’t require exotic manufacturing techniques to reach production. Beyond clothing, the work pushes programmable textiles closer to the rapidly growing field of mechanical metamaterials, where structures derive their unique abilities from geometry rather than complex electronics.

The long-term vision is even more ambitious. The researchers imagine fabrics that quietly monitor body movement, provide tactile feedback, respond to environmental changes, or physically morph into entirely new shapes on demand. Smart textiles have existed for years, but they’ve often relied on rigid sensors and bulky electronics stitched into fabric. Harvard’s approach suggests the fabric itself could eventually become the technology. That’s a subtle shift, but one that could redefine everything from wearable health trackers to adaptive furniture and responsive interiors.