Smart Fabric That Changes Shape on Demand from Harvard Researchers
A Harvard SEAS team has developed multistable fabrics using traditional industrial knitting techniques that can change shape, sense movement, and function as an electrical switch.
Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences have produced smart fabrics that can change shape, sense movement, and act as switches using traditional knitting methods. This newly developed generation of programmable textiles possesses the ability to transition abruptly from one stable form to another.
Development of Multistable Fabrics
Scientists from the Harvard John A. Paulson School of Engineering and Applied Sciences have proven that traditional knitting techniques can be used to produce functional fabrics that change shape, sense movement, and function as switches. The research was led by recent Ph.D. graduate Kausalya Mahadevan, and the results of the study were published in the journal Advanced Functional Materials.
Where Physics Meets Knitted Textiles
The concept of multistability in textiles originated from a combination of inspiration drawn from textile artists and the laboratory's approach to non-linear mechanics in solid matter. The researchers demonstrated that industrial weft knitting methods, commonly used in the production of hats and gloves, can create complex curved structures using only yarn.
Yarn Selection and Special Knitting Method
The team selected highly elastic yarns and utilized a knitting method called plating, which places different yarns on opposite surfaces of the fabric. This combination resulted in dense and thick fabrics that naturally curl into three-dimensional forms.
Stable Transitions Between Shapes
As a result of arranging horizontal and vertical lines with systematic combinations, textiles were obtained that can transition between different configurations and remain stable in each one. This feature allows it to operate just like an electrical switch that stays fixed in either an open or closed position.
Soft and Flexible Electrical Switches
To demonstrate the practical use of the technology in devices, thin conductive yarns were integrated into the structure. These fibers were transformed into soft and flexible electrical switches that change their electrical state as the knitted structures transition from one configuration to another.
Practical Applications and Prototypes
During demonstrations, prototypes were produced including a sleeve that turns an LED on and off as the textile states change, a wearable switch placed over the knee or elbow capable of counting steps, and a reconfigurable lampshade.
Scalable Structure Suitable for Mass Production
The fact that the machines used by the researchers resemble industrial knitting equipment found in garment factories indicates that devices based on this technique can be relatively quickly moved to mass production. In the future, textiles that monitor body movements and provide haptic feedback are targeted.