Nankai University team has obtained pure silk artificial muscle for smart fabrics and flexible robots

- Mar 18, 2019-

Recently, it was learned from Nankai University that the team of Professor Liu Zunfeng, the State Key Laboratory of Medicinal Chemistry Biology, has developed a green and pure silk “artificial muscle” that can automatically expand and contract by sensing humidity. This new type of "artificial muscle" can be used not only for smart fabrics, but also for the development of soft robots.

Combining traditional textile technology with fiber-type "artificial muscles" is one of the ways to obtain smart textiles. Researchers have shown that although fiber materials such as carbon nanotubes, graphene, polyethylene, and nylon have been reported for the preparation of "artificial muscle" fibers, these materials are difficult to use as smart textiles for regulating humidity and body temperature. Because these materials have the disadvantages of high cost, complicated process, and poor comfort. The paper introducing the results was published in the international authoritative journal “Advanced Functional Materials” (the Advanced Functional Materials).

The team of Liu Zunfeng used a natural pure silk to prepare a new type of "artificial muscle" fiber, which was obtained by conventional industrial processes such as degumming, twisting, plying, and heat setting without using chemical modification and additives. The silk "artificial muscle" is driven by water mist and humidity to achieve torsion, stretching and contraction actuation.

In order to achieve reversible driving without external fixation, the Liu Zunfeng team developed a torque-balanced fiber structure that achieved self-balancing by twisting and plying the twisted fibers.

The reporter saw in the lab that the researchers used a silk-stretching muscle to weave a doll-sized smart top, which increased the length of the sleeve of the smart top to the original length when the ambient humidity increased (for example, due to sweat or moisture). Half of it; when the humidity drops, it returns to its original state. This moisture-sensitive textile can be very effective in managing moisture and heat by changing the macro shape.

Liu Zunfeng said that due to the wide application of silk and excellent wearing comfort, the silk artificial muscle production process conforms to the current industrial process, does not require chemical modification and additional additives, and is expected to open up more possibilities in industrial applications. For example, smart textiles and flexible robots.