The stiffness (flexural rigidity) of live sperm flagella, Triton-demembranated flagella (axonemes), trypsin-digested axonemes, and doublet microtubules of the axonemes in echinoderms was determined from the relationship between their deformation when a stream of medium was applied and the viscous resistance of the medium acting on the flagellum. The stiffness of the flagellum beating in seawate...

In this paper, two different piezoelectric microactuator designs are studied. The corresponding devices were designed for optimal in-plane displacements and different high flexibilities, proven by electrical and optical characterization. Both actuators presented two dominant vibrational modes in the frequency range below 1 MHz: an out-of-plane bending and an in-plane extensional mode. Neverthel...

The present paper investigates the advantages of a new class of composite grid structures over conventional grids. Thus far, a known grid structure such as orthogrid or isogrid has been used as an orthotropic layer with at most in-plane anisotropy. The present laminated grid is composed of various numbers of thin composite grid layers. The stiffness of the structure can be adjusted by choosing ...

Experimental evidence for a correlation between paperboard edgewise compressive strength and the product of the in-plane normal stiffness and out-of-plane shear stiffness is presented. A mathematical theory, which describes compressive failure as interlaminae shear failure due to prebuckling bending of an initially curved "critical" lamina, is developed. The theory is in accord with failure ana...

PURPOSE Evidence concerning the alteration of knee function during landing suffers from a lack of consensus. This uncertainty can be attributed to methodological flaws, particularly in relation to the statistical analysis of variable human movement data. The aim of this study was to compare single-subject and group analyses in detecting changes in knee stiffness and coordination during step lan...

We developed an in-plane Atomic Force Microscope (AFM) probe that is specifically tailored to the needs of biological applications. It features a variable stiffness, which makes the stiffness of the probe adjustable to the surface hardness of the sample [1]. The inherent capability of the in-plane AFM probe for building a massively parallel array is also an important feature that greatly affect...

For the nonlinear analysis of structures using the well known Newton-Raphson Method, the tangent stiffness matrices of the elements must be constructed in each iteration. Due to the high expense required to find the exact tangent stiffness matrices, researchers have developed novel innovations into the Newton-Raphson method to reduce the cost and time required by the analysis. In this paper, a ...

This paper presents in-plane electrostatic comb-drive actuators with stroke as large as 245 μm that is achieved by employing a novel Clamped Paired Double Parallelogram (C-DPDP) flexure mechanism. For a given flexure beam length, comb gap, and actuation voltage, this is currently the largest comb-drive actuator stroke reported in the literature. The C-DP-DP flexure mechanism design offers high ...