INTRODUCTION Nano-indentation has recently been employed as a powerful tool for determining the mechanical properties of biological tissues on nano and micro scales. A majority of soft biological tissues such as ligaments and tendons exhibit viscoelastic or time-dependent behaviors. The constitutive characterization of soft tissues is among very important subjects in clinical medicine and espec...

Nanoindentation has recently gained attention as a characterization technique for mechanical properties of biological tissues, such as bone, on the sub-micron level. However, optimal methods to characterize viscoelastic properties of bones are yet to be established. This study aimed to compare the time-dependent viscoelastic properties of bone tissue obtained with different nanoindentation meth...

We present a method to determine elasto-mechanical properties of soft biological tissues, and a device able to perform the required measurements in-vivo. The device permits the controlled application of vacuum to small spots of organic tissue and registers the small deformation caused, during the whole measurement process. Deformation is measured with a vision based technique and the grabbed im...

Ultrasonic elasticity imaging enables visualization of soft tissue deformation for medical diagnosis. Our aim is to understand the role of flow-dependent and flow-independent viscoelastic mechanisms in the response of biphasic polymeric media, including biological tissues and hydrogels, to low-frequency forces. Combining the results of confined and unconfined compression experiments on gelatin ...

The extracellular matrix (ECM) comprises a gel of numerous biopolymers that occurs in a multitude of biological tissues. The ECM provides the basic support and mechanical strength of skeletal tissue and is responsible for shape retention. At the same time, the ECM is responsible for the viscoelastic properties and the elasticity of soft tissues. As expected, there are several important diseases...

Spatiotemporal changes in viscoelasticity are a key component of the morphogenesis living systems. Experimental and theoretical findings suggest that cellular- tissue-scale can be understood as collective property emerging from macromolecular cellular interactions, respectively. Linking structural or material properties cells tissues, such phase transitions, to microscopic interactions their co...

Introduction. In this work the dynamic contact of a hemispherical indenter covered by a thick viscoelastic layer and pressed against a flat rigid surface is modeled. The goal is to investigate the dynamic behavior of robotic fingertips composed by an inner rigid structure covered by a soft layer, mimicking the human biological model. A quasi-linear model, frequently used to describe the behavio...

The importance of understanding the mechanical behavior of tissues is starting to be recognized in medical diagnostics. It is becoming clear that pathological tissues behave mechanically differently than do healthy tissues. However, traditional optical evaluation methods, particularly speckle-based methods, have not proven to be effective in assessing the mechanics of biological soft tissues. T...

The properties of composite materials including those of biological origin depends very much upon structure. We consider here viscoelastic properties in which the stiffness depends on time or frequency, and microelastic properties in which there is dependence of stress upon spatial gradients of strain. The complex structural hierarchy of composite materials, particularly biological ones, gives ...

Accurate characterization of the mechanical behavior of soft tissues is needed for medical simulation, diagnostic, and tissue engineering purposes. Determining the complex behavior of soft tissues requires mechanical testing in their natural state. Such in vivo tests are wrought with ethical, accessibility, physiological noise, and uncontrolled boundary condition issues. Several groups have dev...