In this paper, we report an innovative depth-sensing nanoindenter using a lead zirconium titanate (PZT) stack actuator. The conventional nanoindenter requires two sensors and closed-loop controls for precise loading or positioning due to inherent high hysteresis and creep characteristics of the PZT actuators. On the other hand, we have shown that an open-loop positioning control scheme using a single displacement sensor can be used for nanoindentation. The developed control scheme compensates for the hysteresis and creep errors of PZT actuators. By adopting the single-sensor open-loop control, the overall system structure can be simplified and a robust control environment can be achieved. In addition, a high positioning repeatability was achieved by using a flexure type mainframe with a high preload applied to the PZT actuator. To verify the system performance, we conducted the standard indentation tests on a fused quartz sample, and the results were compared with those from a commercial nanoindenter. Besides the basic nanoindentation functions, the developed system also has the capability for surface imaging through a scanning function. The pre-indentation scanning capability proved to be a very useful method for positioning the tip in the desired indentation location. Similarly, post-indentation scanning allows for visualization of the indentation marks after the tests.
[1]
Suresh K. Sitaraman,et al.
Elastic–plastic characterization of thin films using nanoindentation technique
,
2003
.
[2]
A. Ngan,et al.
Size effects of nanoindentation creep
,
2004
.
[3]
Atsushi Shimamoto,et al.
Development of a depth controlling nanoindentation tester with subnanometer depth and submicro-newton load resolutions
,
1997
.
[4]
Richard J. Colton,et al.
EFFECT OF PZT AND PMN ACTUATOR HYSTERESIS AND CREEP ON NANOINDENTATION MEASUREMENTS USING FORCE MICROSCOPY
,
1994
.
[5]
B. Bhushan,et al.
Nanoindentation and picoindentation measurements using a capacitive transducer system in atomic force microscopy
,
1996
.
[6]
G. Pharr,et al.
An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments
,
1992
.
[7]
K. Zeng,et al.
Analysis of nanoindentation creep for polymeric materials
,
2004
.