Spherical indentation on biological films with surface energy

Indentation measurements on thin films

Thin films have an important part to play in modern technology. It is difficult to characterize the mechanical properties of thin films because the films cannot usually be investigated separately from the substrate. One of the few methods that can be used for such investigations consists in making an indentation in the film by applying an extremely small and accurately controlled force while at...

Microstructure evolution of gold thin films under spherical indentation for micro switches contact applications

RF MEMS (Radio Frequency Micro Electro Mechanical System) switches are promising devices but their gold-on-gold contacts, assimilated for this work to a sphere / plane contact, represent a major reliability issue. A first step towards failure mechanism understanding is the investigation of the contact metal microstructure evolution under static and cyclic loading. After static and cyclic loadin...

Spherical indentation of elastic-plastic solids

The finite-element method is used to perform an accurate numerical study of the normal indentation of an elastic-plastic half-space by a rigid sphere. The effects of elasticity and strain-hardening rate of the half-space are explored, and the role of friction is assessed by analysing the limiting cases of frictionless contact and sticking friction. Indentation maps are constructed with axes of ...

On the measurement of stress–strain curves by spherical indentation

It has been proposed that with the appropriate models, instrumented indentation test (IIT) data can be reduced to yield the uniaxial stress–strain behavior of the test material. However, very little work has been done to directly compare the results from uniaxial tension and spherical indentation experiments. In this work, indentation and uniaxial tension experiments have been performed on the ...

Spherical Indentation Hardness of Shape Memory Alloys