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Displaying 1 - 23 of 23

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

Robust Auto-Alignment Technique for Orientation-Dependent Etching of Nanostructures

May 29, 2012
Author(s)
Craig D. McGray, Richard J. Kasica, Ndubuisi G. Orji, Ronald G. Dixson, Michael W. Cresswell, Richard A. Allen, Jon C. Geist
A robust technique is presented for auto-aligning nanostructures to slow-etching crystallographic planes in materials with diamond cubic structure. Lithographic mask patterns are modified from the intended dimensions of the nanostructures to compensate for

Traceable Calibration of a Critical Dimension Atomic Force Microscope

March 9, 2012
Author(s)
Ronald G. Dixson, Ndubuisi G. Orji, Craig D. McGray, John E. Bonevich, Jon C. Geist
The National Institute of Standards and Technology (NIST) has a multifaceted program in atomic force microscope (AFM) dimensional metrology. One component of this program, and the focus of this paper, is the use of critical dimension atomic force

Rectangular Scale-Similar Etch Pits in Monocrystalline Diamond

September 15, 2011
Author(s)
Craig D. McGray, Richard A. Allen, Marc J. Cangemi, Jon C. Geist
Etching of monocrystalline diamond in oxygen and water vapor at 1100° C through small pores in a silicon nitride film produced smooth-walled rectangular cavities. The cavities were imaged by electron microscope and measured by interferometric microscopy

Traceable Calibration of a Critical Dimension Atomic Force Microscope

June 6, 2011
Author(s)
Ronald G. Dixson, Ndubuisi G. Orji, Craig D. McGray, Jon C. Geist
The National Institute of Standards and Technology (NIST) has a multifaceted program in atomic force microscope (AFM) dimensional metrology. One component of this effort is a custom in-house metrology AFM, called the calibrated AFM (C-AFM). The NIST C-AFM

Progress on CD-AFM tip width calibration standards

May 10, 2011
Author(s)
Ronald G. Dixson, Boon Ping Ng, Craig D. McGray, Ndubuisi G. Orji, Jon C. Geist
The National Institute of Standards and Technology (NIST) is developing a new generation of standards for calibration of CD-AFM tip width. These standards, known as single crystal critical dimension reference materials (SCCDRM) have features with near

MEMS Young's Modulus and Step Height Measurements with Round Robin Results

September 30, 2010
Author(s)
Janet M. Cassard, Richard A. Allen, Craig D. McGray, Jon C. Geist
This paper presents the results of a microelectromechanical systems (MEMS) Young s modulus and step height round robin experiment, completed in April 2009, which compares Young s modulus and step height measurement results at a number of laboratories. The

Mobile Microrobot Characterization through Performance-Based Competitions

November 19, 2009
Author(s)
Jason J. Gorman, Craig D. McGray, Richard A. Allen
Recent advances in the design and fabrication of microelectromechanical systems (MEMS) have enabled the development of mobile microrobots that can autonomously navigate and manipulate in controlled environments. It is expected that this technology will be

MEMS in Action: RoboCup Nanogram 2009

August 1, 2009
Author(s)
Richard A. Allen, Craig D. McGray
From June 29 through July 5, 2009 teams from around the world participated in the International RoboCup competition, held in Graz, Austria. In addition to humanoid robots playing soccer on turf fields, companion robots demonstrating their ability to help

The Study of the U.S. Measurement System for Micro Nano Technologies

September 1, 2006
Author(s)
Richard A. Allen, Craig McGray, Michael Gaitan
The National Institute of Standards and Technology (NIST) has launched an ambitious assessment of the nation''s decentralized measurement system, that is far more encompassing than the few studies done over the last several decades. The aim is to determine