Silk has always been a high-endclothing fabric ’s raw materials are also gradually being used in high-tech fields such as bioengineering, flexible sensors, optical storage, flexible electronic devices and soft actuators. However, the irregular morphology, structure and performance differences between individuals of natural silk are very obvious, which greatly limits the industrial application of silk in high-tech fields. In order to improve the morphology and performance of silk materials, methods such as regenerative spinning, feed modification, injection of metal ions, gene editing, and artificial forced spinning have emerged. Among them, artificial forced spinning technology has been proven to be an ideal method to obtain high-performance silk, but how to alleviate or eliminate the resistance behavior of silkworms during the spinning process and obtain silk with excellent performance is still a huge challenge.
To solve this problem, the Zhejiang Sci-Tech University research team creatively A multi-mode, rapid centrifugal spinning method was developed to prepare high-strength, high-modulus, and high-tenacity silk (CRS). The spinning speed of this method can be more than 6 times that of natural spinning, and the collected CRS has excellent breaking strength, comparable to spider silk.
Multi-mode centrifugal spinning strategy inspired by spiders’ suspended silk spinning Inspired by the inspiration, the team designed a cone carrier with adjustable angle to support the silkworm body to spin silkworms in a nearly suspended state; at the same time, they took advantage of the intermittent spinning phenomenon of silkworms during their natural cocooning process. Intermittent spinning is performed, that is, after continuous extraction for a certain period of time, the spinning operation is stopped to allow the silkworms sufficient time to adapt to the spinning process; finally, silk can be prepared in one step by rotating the cone carrier and increasing the number of silkworms spinning Yarn(CRSY).
The study found that non-head-end fixed spinning and intermittent spinning It is beneficial to alleviate the resistance behavior of silkworms during forced spinning. The length of silk obtained by intermittent spinning is significantly longer at the first break than that of silk collected by continuous extraction, which can be used as an important indicator to quantify the resistance behavior of silkworms.
Researchers compared CRS with cocoon silk (CS), head The breaking strength, toughness and Young’s modulus of strong tensile silk, spider silk, cotton and wool are fixed internally. The results show that compared with cocoon silk, the breaking elongation of CRS is increased by about 50%, the breaking strength is increased by about 5% to 15%, the toughness is (121.07±35.31) MJ/m3, and the Young’s modulus is (27.72±12.61 )GPa; its maximum breaking strength can reach 1.45GPa, which is 3 times that of natural cocoon silk. Continue to increase the number of silk-spinning silkworms. When the cone carrier rotates, one-step preparation from silk to yarn can be achieved. When the silk is broken or the silkworms no longer spin silk, the silk-spinning silkworms can be replenished by twisting and twisting to achieve Continuous preparation of silk yarn.
In addition to excellent mechanical properties, CRS also has fast torsional recovery performance, and can still maintain good recovery effects after multiple cycles, making it an excellent micro-actuator material. CRSY-based pneumatic soft actuators can perform preset actions, including contraction, extension, and bending, and can bear extremely high loads, fully demonstrating the application potential of CRSY in the fields of artificial muscles, soft actuators, and soft robots.
Related results are titled “High-performance artificially reeled silkworm silk via a “Multi-task and high-efficiency centrifugal reeling technique and its application in soft actuators” was published in “Materials Horizons”.
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