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Displaying 1 - 25 of 46

Accurate localization microscopy by intrinsic aberration calibration

June 24, 2021
Author(s)
Craig Copeland, Craig McGray, Robert Ilic, Jon Geist, Samuel Stavis
A standard paradigm of localization microscopy involves extension from two to three dimensions by engineering information into emitter images, and approximation of errors resulting from the field dependence of optical aberrations. We invert this standard

Particle tracking of microelectromechanical system performance and reliability

October 25, 2018
Author(s)
Craig R. Copeland, Craig D. McGray, Jon C. Geist, Samuel M. Stavis
Microelectromechanical systems (MEMS) that require contact of moving parts to implement complex functions have demonstrated critical limits of performance and reliability. Here, we advance a particle tracking method to measure MEMS motion in operando at

Subnanometer localization accuracy in widefield optical microscopy

July 11, 2018
Author(s)
Craig R. Copeland, Jon C. Geist, Craig D. McGray, Vladimir A. Aksyuk, James A. Liddle, Bojan R. Ilic, Samuel M. Stavis
The common assumption that precision is the limit of accuracy in localization microscopy and the typical absence of comprehensive calibration of optical microscopes lead to a widespread issue - overconfidence in measurement results with nanoscale

Aperture Arrays for Subnanometer Calibration of Optical Microscopes

September 28, 2017
Author(s)
Craig Copeland, Craig McGray, Jon Geist, James Alexander Liddle, Robert Ilic, Samuel Stavis
We fabricate and test subresolution aperture arrays as calibration devices for optical localization microscopy. An array pitch with a relative uncertainty of approximately three parts in ten thousand enables magnification calibration with subnanometer

Centroid and Orientation Precision of Localization Microscopy

March 11, 2016
Author(s)
Craig D. McGray, Craig R. Copeland, Samuel M. Stavis, Jon C. Geist
The concept of localization precision, which is essential to localization microscopy, is formally extended from optical point sources to microscopic rigid bodies. Measurement functions are presented to calculate the planar position, orientation, and motion

Characterization of Electrothermal Actuation with Nanometer and Microradian Precision

June 21, 2015
Author(s)
Craig R. Copeland, Craig D. McGray, Jon C. Geist, Vladimir A. Aksyuk, Samuel M. Stavis
A recently introduced particle-tracking method was used to measure the single motion cycles of an electrothermal actuator with nanometer and microradian precision. Driving the actuator with a low-noise input induced deterministic motion that was perfectly

Method for Measuring Axis Orthogonality in MEMS Accelerometers

July 15, 2013
Author(s)
Craig D. McGray, Muhammad Y. Afridi, Jon C. Geist
A method is described for the computation of axis orthogonality errors in 3-axis accelerometers, based on the application of gravitational force at known angles. A precision two-axis articulated gimbal system is used to control the angle at which the

The MEMS 5-in-1 Test Chips (Reference Materials 8096 and 8097)

March 27, 2013
Author(s)
Janet M. Cassard, Jon C. Geist, Craig D. McGray, Richard A. Allen, Muhammad Y. Afridi, Brian J. Nablo, Michael Gaitan, David G. Seiler
This paper presents an overview of the Microelectromechanical Systems (MEMS) 5-in-1 Reference Material (RM), which is a single test chip with test structures from which material and dimensional properties are obtained using five documentary standard test

MEMS Kinematics by Super-Resolution Fluorescence Microscopy

September 27, 2012
Author(s)
Craig D. McGray, Samuel M. Stavis, Joshua Giltinan, Eric Eastman, Samara L. Firebaugh, Jenelle Piepmeier, Jon C. Geist, Michael Gaitan
Super-resolution fluorescence microscopy is used for the first time to study the nanoscale kinematics of a MEMS device in motion across a surface. A device under test is labeled with fluorescent nanoparticles that form a microscale constellation of near
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