elastometri

Elastometry is the measurement of the elastic properties of a material or biological tissue. The term encompasses techniques that quantify how a substance deforms under applied forces and how it recovers its shape when those forces are removed. Common results include elastic moduli such as Young’s modulus and shear modulus, as well as viscoelastic parameters like storage and loss moduli.

Principles and methods: Elastometry can be performed with direct mechanical testing, where a specimen is subjected to uniaxial tension, compression, or shear and the resulting stress–strain response is recorded. Indentation methods use a probe to press into the material and relate force and displacement to a modulus. Rheological techniques examine the material under oscillatory loading to derive a complex modulus. In medical contexts, elastography methods infer tissue stiffness from propagating waves or imaging data, producing spatial maps of elasticity.

Devices and setups: Conventional elastometers and rheometers are used for polymers and elastomeric materials. Indentation devices, durometers, and nanoindenters provide local measurements at small scales. For medical applications, ultrasound- or magnetic resonance-based elastography, as well as surface-indentation tools, are common.

Applications: Elastometry supports material characterization in industry, including polymers, rubbers, composites, coatings, and elastomeric components, aiding quality control and design. In biomechanics and medicine, it helps assess tissue mechanics, investigate disease progression, and monitor liver fibrosis or muscular function. In geophysics, elastometry contributes to estimating rock and soil properties through targeted mechanical testing.

Limitations: Results depend on geometry, boundary conditions, strain rate, and measurement scale. Different methods probe different frequency ranges and yield different moduli, so direct comparisons require careful interpretation, especially for viscoelastic materials.