assessing the behavior of composite structures which are subjected to impact loads is one of the important subjects in the field of mechanical sciences. using thin-walled tubes which collapsed and absorbed the impact energy is a well-known method to prevent damages to the other parts of the structures. in this paper, deformations, crushing length, peak load, mean force and energy absorption cap...

the presence of van der waals (vdw) force can lead to mechanical instability in freestanding nano-scale actuators. most of the previous researches in this area have exclusively focused on modeling the instability in actuators with one actuating components. while, less attention has been paid to actuators consist of two actuating components. herein, the effect of the vdw force on the instability...

Actomyosin contractility affects cellular organization within tissues in part through the generation of mechanical forces at sites of cell-matrix and cell-cell contact. While increased mechanical loading at cell-matrix adhesions results in focal adhesion growth, whether forces drive changes in the size of cell-cell adhesions remains an open question. To investigate the responsiveness of adheren...

Titin I27 shows a high resistance to unfolding when subject to external force. To investigate the molecular basis of this mechanical stability, protein engineering Phi-value analysis has been combined with atomic force microscopy to investigate the structure of the barrier to forced unfolding. The results indicate that the transition state for forced unfolding is significantly structured, since...

The structural integrity of human skin is largely dependent on the quality of the dermal extracellular matrix (ECM), which is produced, organized, and maintained by dermal fibroblasts. Normally, fibroblasts attach to the ECM and thereby achieve stretched, elongated morphology. A prominent characteristic of dermal fibroblasts in aged skin is reduced size, with decreased elongation and a more rou...

one of the bio-sensing mechanisms is mechanical. rather than measuring shift in resonance frequency, we adopt to measure the change in spring constant due to adsorption, as one of the fundamental sensing mechanism. this study explains  determination of spring constant of a surface functionalized micro machined micro cantilever, which resonates in a trapezoidal cavity-on silicon wafer, with the ...

The mechanical properties of proteins are crucial in living cells as proteins serve as basic units in cells to constantly sense, generate, and bear mechanical forces. Outside the cell, nature exploits the mechanical features of proteins and produces a variety of materials with superb mechanical properties (e.g. spider dragline silk) which often outperform man-made materials. Studies of the mech...

One of the main milestones in the study of opto-mechanical system is to increase the sensitivity of weak forces measurement up to the standard quantum limit. We have studied the detection of weak force under a bistable condition in red detuned regime. In this case, dynamics of the system behaves asymptotically similar to stationary state and applying external force affects phase and fluctuation...

An approach for achieving reliable, built-in, high-accuracy force sensing for legged robots is presented, based on direct exploitation of the properties of a robot’s mechanical structure. The proposed methodology relies on taking account of force-sensing requirements at the robot design stage, with a view to embedding force-sensing capability within the mechanical structure of the robot itself....

Mechanical stimuli profoundly alter cell fate, yet the mechanisms underlying mechanotransduction remain obscure because of a lack of methods for molecular force imaging. Here to address this need, we develop a new class of molecular tension probes that function as a switch to generate a 20- to 30-fold increase in fluorescence upon experiencing a threshold piconewton force. The probes employ imm...