United States of America as Represented by the Administrator of Nasa

Phillip B Abel

Philip G Neudeck

J Anthony Powell

Othmane Benafan

Steven W Bauman

Paul A Solano

Darrell J Gaydosh

A plurality of shape memory alloy tubes (SMTs) of one or more shape memory alloy (SMA) types is configured as an element in a rotary actuator system in a nested manner. In various configurations, the nested SMTs provide one or more modes of multiplication (torque output or angular displacement), rotation reversibility and bias loading. The innovation provides for leveraging the modes for reductions in the rotary actuator system size, weight, or complexity or combinations thereof, or providing improved and more stable actuation capabilities in a given envelope.

Shape memory alloy nested rotary actuator

Methods are disclosed that provide for structures and techniques for the fabrication of ordered arrangements of crystallographically determined nanometer scale steps on single crystal substrates, particularly SiC. The ordered nanometer scale step structures are produced on the top surfaces of mesas by a combination of growth and etching processes. These structures, sometimes referred to herein as artifacts, are to enable step-height calibration, particularly suitable for scanning probe microscopes and profilometers, from less than one nanometer (nm) to greater than 10 nm, with substantially no atomic scale roughness of the plateaus on either side of each step.

Method for the production of nanometer scale step height reference specimens

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Cleveland, OH, United States of America

Phillip B Abel