Biological activity gives rise to nonequilibrium fluctuations in the cytoplasm of cells; however, there are few methods to directly measure these fluctuations. Using a reconstituted actin cytoskeleton, we show that the bending dynamics of embedded microtubules can be used to probe local stress fluctuations. We add myosin motors that drive the network out of equilibrium, resulting in an increase...

The thermal motion of stiff filaments in a crowded environment is highly constrained and anisotropic; it underlies the behavior of such disparate systems as polymer materials, nanocomposites, and the cell cytoskeleton. Despite decades of theoretical study, the fundamental dynamics of such systems remains a mystery. Using near-infrared video microscopy, we studied the thermal diffusion of indivi...

Bending with high curvature is one of the major mechanical properties of double-stranded DNA (dsDNA) that is essential for its biological functions. The emergence of a kink arising from local melting in the middle of dsDNA has been suggested as a mechanism of releasing the energy cost of bending. Herein, we report that strong bending induces two types of short dsDNA deformations, induced by two...

Common finite element programs for plate bending analysis are complicated and limited by the common plate theories. Such programs are usually not user-friendly for designers to implement. Lately, Hou Man et al. from the University of New South Wales has developed a technique for unified 3D plate bending analysis using scaled boundary finite element analysis, which promises to have little restri...

The consideration of biomechanical alterations due to intervertebral disc (IVD) degeneration is crucial for the accurate analysis of spine biomechanics. In this study, finite element (FE) models of the L4-L5 functional spinal unit with full coverage of the degeneration grades from healthy IVD to severe degeneration were developed. The effects of IVD degeneration on spine biomechanics were analy...

This paper presents feedforward, feedback and two-degree-of-freedom control applied to an Ionic Polymer-Metal Composite (IPMC) actuator. It presents a high potential for development of miniature robots and biomedical devices and artificial muscles. We have reported in the last few years that dehydration treatment improves the electrical controllability of bending in Selemion CMV-based IPMCs. We...

the creep/recovery behavior of wood flour-polypropylene was compared with medium density fiberboard (mdf) and particleboard. for this purpose, wood flour-polypropylene composites (with and without compatibilizer)were manufactured by using a laboratory twin-screw extruder. the mdf and particleboard panels were obtained from local producers. short term flexural creep tests at 30% of ultimate bend...

Rapid progress in the reduction of substrate thickness for silicon-based microelectronics leads to a significant reduction of the device bending stiffness and the need to address its implication for the thermo-mechanical fatigue behavior of metallization layers. Results on 5 µm thick Cu films reveal a strong substrate thickness-dependent microstructural evolution. Substrates with hs = 323 and 2...

The conformation and scaling properties of self-avoiding fluid membranes with an extrinsic bending rigidity kappa were studied with the use of Monte Carlo methods. For kappa = 0, the results are consistent with branched polymer behavior at large length scales. There is a smooth crossover from a crumpled to an extended state with increasing kappa, with a peak in the specific heat when the persis...

We present a triangular six-node shell element that represents an important improvement over a recently published element [1]. The shell element is formulated, like the original element, using the MITC procedure. The element has the attributes to be spatially isotropic, to pass the membrane and bending patch tests, to contain no spurious zero energy mode, and is formulated without an artificial...