Colloquium: Dr. Mehmet Kanik, Massachusetts Inst. of Tech

Mimicking the structure of the cucumber tendrils, we developed a fiber based artificial muscle that possess the similar functions observed in mammalian muscle such as agility, and feedback. The artificial muscle devices were produced using cost effective thermal draw method in extended (10 3 – 10 4 m)

lengths and arbitrary scales in 5 μm to 5 mm thickness range. The fiber muscle is a bimorph structure which is made of an elastomer and thermoplastic polymer with low thermal expansion coefficient and high expansions, respectively. The fiber muscle self-assembles in helical shape after stretching and releasing. The size and the number of the coils in the helical can be programmed by the applied strain and strain rate. The fiber muscles can be optically and thermally actuated in ambient temperature

(ΔT=10 oC). Fiber muscles demonstrate a very rapid force switch rate of 6.33±0.72 N/s and a power-to- mass ratio 75–90 Wkg-1 .They can be contracted up to 50 % and stretched up to 1300 %. Fiber muscles can lift weights 650 times higher than their own weight. To enable a feedback mechanism, we outfitted the muscle fibers with Ag nanowire meshes. When the fiber muscles were contracted and extended, the change in the length of the fiber was exported as a relative resistance change signal. We developed an artificial arm inspired by human arm and driven by the artificial muscle fiber. The movement of the arms was flowing naturally similar to human muscle movements. The muscle fibers with arbitrary scalability, high performance and very low latency can likely find application not only in robotics and prosthetic limb technologies, but also in smart textile, implantable sensor, and neural engineering.