An adaptive nanoindentation system based on electric bending of a piezoelectric cantilever

• We propose a nanoindentation system based on a piezoelectric cantilever.
• Only the cantilever strain signal is monitored to extract the load–depth curve.
• The nanoindentation system is compact and adaptive.
• Performance of the system is validated by experimental investigations.
• The system is especially suitable for in situ nanomechanical measurements.

In this work, we proposed a compact and adaptive nanoindentation (NI) method/system in which the indentation process is accomplished by electric bending of a piezoelectric unimorph cantilever with a diamond Berkovich indenter on its free end. A very sensitive strain gauge is bonded on its top surface to sense the cantilever indenter's displacement and the indention load, which leads to the load–depth curve and then the elastic properties of the testing sample. Both the maximum indentation load and depth of this NI system are dependent on the sample's modulus, and can be tunable by varying the cantilever's dimensions and the applied voltage. The performance of the proposed NI system is examined through testing on different materials with the modulus in the range of 10 MPa–100 GPa and the results show good agreements with that given by a commercial NI instrument. The proposed NI method offers a simple solution for the otherwise complex indentation testing, which is very promising for in situ mechanical characterization of various materials.