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Search Publications by: Gregory A Cooksey (Fed)

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Displaying 1 - 24 of 24

Optofluidic Flow Meter for sub-nanoliter per minute flow measurements

January 31, 2022
Author(s)
Jalal Sadeghi, Paul Patrone, Anthony J. Kearsley, Gregory A. Cooksey
Performance improvements in microfluidic systems depend on accurate measurement and control of fluids on the micro- and nanoscale, and new applications are continuously moving the needle to lower volumetric flow rates. This work focuses on improving an

Matching and comparing objects in a serial cytometer

October 4, 2020
Author(s)
Nikita Podobedov, Matthew DiSalvo, Jason A. Hsu, Paul Patrone, Gregory A. Cooksey
Flow cytometers are indispensable for clinical studies, yet are hindered by inherent uncertainties. We have developed an optofluidic device capable of multiple measurements along a microfluidic channel, whereby many of the uncertainty components can be

Serial microfluidic cytometry with inertial and hydrodynamic flow focusing

October 4, 2020
Author(s)
Matthew DiSalvo, Paul Patrone, Gregory A. Cooksey
Microfluidics are increasingly used to develop flow cytometers with novel functionalities. Although various approaches exist to control particle positioning within microfluidics, the magnitude and mechanisms of measurement uncertainties that arise from

DYNAMIC MEASUREMENT OF NANOLITER PER MINUTE FLOW BY SCALED DOSAGE OF FLUORESCENT SOLUTIONS

October 3, 2020
Author(s)
Gregory A. Cooksey, Paul Patrone, James R. Hands, Stephen E. Meek, Anthony J. Kearsley
This work describes a new method for continuous measurement of flow in a microchannel from 1 nL/min to 1000 nL/min using an optofluidic device with waveguides that deliver and collect light from small regions of a microfluidic channel. By relating the

Measuring Microfluidic Flow Rates: Monotonicity, Convexity and Uncertainty

August 20, 2020
Author(s)
Paul Patrone, Qing Hai Li, Gregory A. Cooksey, Anthony J. Kearsley
A class of non-linear integro-differential equations characterizing microfluidic measurements is considered. Under reasonable conditions, these non-linear integro-differential equations admit solutions that are convex functions of an interesting flow-rate

The Art in Science of MicroTAS 2019†

July 28, 2020
Author(s)
Gregory A. Cooksey
The 2019 MicroTAS conference (the 23rd International Conference of Miniaturized Systems for Chemistry and Life Sciences) held in Basel, Switzerland, brought great opportunities to viewinspiring microscale compositions. Many of the best images were

The Art in Science of MicroTAS 2018

June 21, 2019
Author(s)
Gregory A. Cooksey
The 2018 MicroTAS conference (the 22nd International Conference of Miniaturized Systems for Chemistry and Life Sciences) took us to Kaohsiung, Taiwan, for an inspiring mix of science and culture. The Art in Science competition, sponsored by Lab on a Chip

Integrated Optical Waveguides for in situ Microflow Measurements

October 15, 2017
Author(s)
James R. Hands, Gregory A. Cooksey
The need for quantitative microscale chemical and biological experiments has resulted in the increasing utilization of microfluidics with integrated sensors, allowing such architectures to synergistically enhance function and performance [1]. This work

Design, sensitivity analysis, and testing of a Caenorhabditis elegans nanoecotoxicity assay

August 11, 2016
Author(s)
Shannon Hanna, Gregory A. Cooksey, Bryant C. Nelson, John T. Elliott, Elijah J. Petersen
Increasing production and usage of engineered nanomaterials (ENMs) has generated widespread interest in measuring their environmental and human health effects. However, the lack of standardized methods for these measurements has often led to contradictory

Performance Benchmarking and Intensity Calibration of a Widefield Fluorescence Microscope Using Fluorescent Glass

August 11, 2014
Author(s)
Michael W. Halter, Elianna Bier, Paul C. DeRose, Gregory A. Cooksey, Steven J. Choquette, Anne L. Plant, John T. Elliott
Widefield fluorescence microscopy is a highly used tool for visually assessing biological samples and for quantifying cell responses. Despite its widespread use in high content analysis and other screening applications, few published methods exist for

A robust diffusion-based gradient generator for dynamic cell assays.

January 1, 2012
Author(s)
Francisco J. Atencia, Gregory A. Cooksey, Laurie E. Locascio
This manuscript describes a new method to generate purely diffusive chemical gradients that can be modified in time. The device is simple in its design and easy to use, which makes it amenable to study biological processes that involve static or dynamic

Reproducibility and Robustness of a Real-Time Microfluidic Cell Toxicity Assay

May 15, 2011
Author(s)
Gregory A. Cooksey, John T. Elliott, Anne L. Plant
Numerous opportunities exist to apply microfluidic technology to high-throughput and high-content cell-based assays. However, maximizing the value of these assays for drug discovery, screening or toxicity evaluation, for example, will require validation of

Magnetic connectors for microfluidic applications

January 1, 2010
Author(s)
Francisco J. Atencia, Gregory A. Cooksey, Andreas Jahn, Justin M. Zook, Wyatt N. Vreeland, Laurie E. Locascio
We present a new type of connector based on a simple idea: using a ring magnet on one side of the microfluidic chip and a disc magnet on the other side to provide the interfacial force necessary to provide a sealed connection between tubing or needles and

A vacuum manifold for rapid world-to-chip connectivity of complex PDMS microdevices

January 1, 2009
Author(s)
Gregory A. Cooksey, Anne L. Plant, Francisco J. Atencia
The lack of simple interfaces for microfluidic devices with a large number of inlets significantly limits production and utilization of these devices. In this paper, we describe the fabrication of a reusable manifold that provides rapid world-to-chip