Williams P A, Papadakis S J, Patel A M, Falvo M R, Washburn S, Superfine R
Department of Physics and Astronomy, University of North Carolina at Chapel Hill, 27599, USA.
Phys Rev Lett. 2002 Dec 16;89(25):255502. doi: 10.1103/PhysRevLett.89.255502. Epub 2002 Nov 27.
We report on the characterization of torsional oscillators which use multiwalled carbon nanotubes as the spring elements. Through atomic-force-microscope force-distance measurements we are able to apply torsional strains to the nanotubes and measure their torsional spring constants, and estimate their effective shear moduli. The data show that the nanotubes are stiffened by repeated flexing. We speculate that changes in the intershell mechanical coupling are responsible for the stiffening.
我们报道了以多壁碳纳米管作为弹簧元件的扭转振荡器的特性。通过原子力显微镜的力-距离测量，我们能够对纳米管施加扭转应变并测量其扭转弹簧常数，同时估计它们的有效剪切模量。数据表明，纳米管通过反复弯曲而变硬。我们推测壳间机械耦合的变化是变硬的原因。
