D. Lu; J. Liu; M. Wang; S. Gu
Sensors 25 (2025) 609
Force–displacement transducers are key components in in situ nanoindentation
systems. The current existing capacitance-type transducers adopted in state-of-the-art
commercial in situ nanoindentation systems are restricted by limited maximum ranges,
and strain gauge-type transducers in the current in situ nanoindentation systems have
the limitation of low resolution and high values of mass. In the paper, we propose a
mechanical design and improvement of a low-mass strain gauge-type force–displacement
transducer capable of performing high resolution in situ nanoindentation measurements.
The transducer mainly consisted of a parallelogram-shaped flexure hinge and two strain
gauges. Air resolution, in situ resolution, and mass experiments reported an air force
resolution of 5 µN, an in situ force resolution of 5 µN inside a scanning electron microscope
(SEM), and a mass of 6.53 g of such a strain gauge-type load–displacement transducer. Then,
the transducer was assembled into a newly developed in situ nanoindentation–atomic force
microscope (AFM) hybrid system and a newly developed in situ nanoindentation system.
The proposed design successfully performed nanoindentation measurements inside SEM.
Based on the results, the proposed strain gauge-type transducer shows great advantages
compared to the current state-of-the-art transducers.