Introduction

• The PI 95 TEM PicoIndenter instrument from Hysitron, Inc. is the first full-fledged depth-sensing indenter capable of direct-observation nanomechanical testing in a transmission electron microscope (TEM). This pioneering in-situ instrument is specifically designed to overcome the numerous configurational and environmental challenges presented by TEMs, and its primary function is to output a quantitative force-displacement curve to be time correlated to the corresponding TEM movie of the stress-induced deformation process. This coupling of high-resolution techniques enables a researcher to witness, for example, the microscopic origin of a measured force or displacement transient.
• Novel in-situ technology:  The key enabling technology of the TEM PicoIndenter instrument is its novel miniature transducer. With this newly-developed transducer, in-situ force-displacement curves can be acquired in a highly accurate depth-sensing manner, instead of relying on an inherently troublesome series-loading, spring-deflection-force scheme. Furthermore, substantially larger forces can be realized on account of the electrostatic actuation aspect of the transducer, without suffering a force sensitivity penalty. Control of the transducer and of the piezoelectric actuator, is governed by a newly developed advanced digital controller operating at a high loop rate.