Articles About Our Research In The Popular Press

New Method to Detect Oxygen Consumption in the Brain

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A novel optical technique enables real-time measurement of the cerebral metabolic rate of oxygen consumption. Image courtesy of Shutterstock.

A Novel Method for Monitoring the ‘Engine’ of Pregnancy

Placenta imaging graphic

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Michael S. Feld Biophotonics Award of the Optical Society of America (2021)

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Scaling of relaxation and excess entropy in plastically deformed amorphous solids

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Better Motion Detection Improves fNIRS Brain Imaging

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SPIE, the International Society for Optics and Photonics
19 February 2020, By Chris Lee

SPIE 2.19.20 graphic

Nature imageDrops of liquid crystal molecules branch out into strange structures

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Penn Physicists Discover Why Drying Liquid Crystal Drops Leave Unusual ‘Coffee Rings’

Friday, May 26, 2017
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“Why drying liquid crystal drops leave unusual ‘coffee rings'”
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“Why Light Matters”

October 27, 2015
In collaboration with The Franklin Institute & PI-Philly, Professional Italians Philadelphia, on the occasion of the 2015-International Year of Light.

Overview @ 11:00 minute mark
Introductions @ 12:45 minute mark
Arjun Yodh, “Imaging “Physiology” Inside the Human Body with Light” from 13:30-36:00 minute mark

Chiral Liquid Crystal Structures and Defects in Cylinders

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New Water-based Liquid Crystal Configurations Discovered
By James Anderson, April 2015.

Solid-Solid Transitions with Intermediate Liquid Phase

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Crystal-crystal transitions: Mediated by a Liquid
By Eduardo Sanz and Chantel Valeriani
Nature Materials, January 2015.

Why do mosquito eggs cling together?

“Why do mosquito eggs cling together? The strange physics of self-assembling structures.”
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Devices Could Improve Stroke Patient Management

“Diffuse Optical Blood Flow Monitor Could Aid in Stroke Management”

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Liquid Crystal Gemstones

“Liquid crystal turns water droplets into ‘gemstones'”
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“Liquid Crystals move beyond television”
by Bookyung Jo, February 5, 2014
The Daily Pennsylvanian

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Diffuse Optics Probes Stuttering

“Find Your Voice: Unlocking the Mysteries of Stuttering

Glen Tellis, Rickson C. Mesquita, and Arjun G. Yodh
July 29, 2013
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Colloidal Particle Growth Front Dynamics Test Universal Equation

“Coffee rings and coffee disks: Physics on the edge”
Physics Today

Peter J. Yunker, Douglas J. Durian, and Arjun G. Yodh
August 2013, page 60
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“Focus: Coffee Stains Test Universal Equation”

By Kim Kreiger
APS Physics Forum (Physics: spotlighting exceptional research) January 2013
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Physicists Help Show Math Behind Growth of ‘Coffee Rings’

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Empirical Zeal Blog

The Universal laws behind growth patterns, or what Tetris can teach us about coffee stains.

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Suppression of the coffee-ring effect by shape-dependent capillary interactions

“Fluid mechanics: When shape matters” By Jan Vermant
Nature (News & Views) August 18, 2011.
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“Scientists Crack the Physics of Coffee Rings” By Joe Palca
National Public Radio (All Things Considered)
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“Why do coffee rings form? Because the grounds are round.” By Veronique Greenwood
Discover Magazine (80beats)
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“Kicking The Coffee-Ring Habit,
Fluid Mechanics: Shift in particle shape suppresses vexing effect” By Bethany Halford
Chemical & Engineering News (August 22, 2011)
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Mechanics of Disordered Solids

“Physicists develop new insight into how disordered solids deform”
Nanowerk News (August 31, 2011)
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Nonlinear Optics of Colloidal Particles

Nonlinear optics in spheres: from second harmonic scattering to quasi-phase matched generation in whispering gallery modes. G. Kozyreff, J.L. Dominguez-Juarez, J. Martorell, Laser & Photonics Reviews Volume 5, Issue 6, pages 737–749, November 2011

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How Thin Films Melt

If you heat a crystal that is just a few molecules thick, it melts differently from a macroscopically thick crystal. A team using gel-like beads in liquid as stand-ins for molecules examined melting in this “thin film” regime by tracking the motion of each particle. As they report in the 21 May Physical Review Letters, …
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Melting Mechanisms in Bulk (3D) Crystals

“Penn physicists are the witnesses to a meltdown.” By Faye Flam, Philadelphia Inquirer, p. E1, July 11, 2005.

“Premelting on the inside.” By Stuart A. Borman, Chemical & Engineering News, p. 21, vol. 83, July 4, 2005.

“Inside a melting crystal.” By A. Goho, Science News, p. 4, vol. 168, July 2, 2005.

“Freezing and Melting: Action at Grain Boundaries,” by Peter N. Pusey, Science 309, 1198-1199 (2005)

“Premelting within Crystals Provides Solution,” by Mark Telford, Materials Today, Page 9, (September 2005)



Of Traffic Jams, Beach Sands And The Zero-Temperature Jamming Transition

Stroke Monitoring

Post-stroke blood flow monitor developed

Photo credit: Candace diCarlo

New MRSEC Director

Penn Current: Q&A/Arjun Yodh


Taking a Closer Look at Glass (w/Peter Yunker)

Physicists Find a World of Motion In the Mystery of Aging Glass

Watching glass age in slow motion


Microscale System To Study Frustration In Buckled Monolayers Of Microspheres

Nature 456, 886-887 (18 December 2008) News and Views (Mark Harris, author):
Condensed-matter physics: The eternal triangle

BioOptics Pioneers

“Bio Optics World Magazine Articles, Arjun G. Yodh”
pdf of article

Brownian Motion of Ellipsoid

Mouvement brownien: redécouverte et tests d’une théorie “perdue”

“Physicists test ‘forgotten’ Brownian motion theory”’forgotten’_Brownian_motion_theory

“Physicists track the random walks of ellipsoids, test ‘lost’ theory of Brownian motion”

Random Walks of Ellipsoids
“Experiments finally test the theory put forward by Francis Perrin in the 1930s”

Carbon Nanotube Aerogels

“Carbon nanotube aerogels”
By Michael Berger, Copyright 2007 Nanowerk LLC

“Materials science: Heavyweight lightweight”

“Carbon nanotube aerogels”
By Francis Sedgemore

Carbon Nanotubes

“Carbon Nanotube Gel”
Number 672 #2, February 2, 2004
by Phil Schewe, James Riordon, and Ben Stein

“Nanotubes gel together for alignment”
Author: Liz Kalaugher

“Surfactant curtails nanotube clumping in water”

Fluorescence Diffuse Optical Tomography of Breast Cancer

“Fluorescence Diffuse Optical Tomography Provides High Contrast, 3-D Look At Breast Cancer”

“Fluorescence diffuse optical tomography provides high contrast, 3-D look at breast cancer”

Photonic Materials

“Building better photonic crystals.” By Robert F. Service, Science, p. 2399, vol. 295, March 29, 2002.

Laser Tweezers for Measurements of Colloidal Interactions

“Bend the rod, spoil the spacing.” By Hank Hogan, Biophotonics International, p. 27, vol. 8, December 2001.

“Scientists grasping the elements of life.” By Faye Flam, Philadelphia Inquirer, p. D1, March 20, 2000.

Diffuse Light for Biomedical Optical Functional Imaging and Spectroscopy

“Diffusion waves and their uses.” By Andreas Mandelis, Physics Today, p. 29, vol. 53, August 2000.

“Scattered light detects cancer.” By Arjun Yodh, Physics World, p. 28, vol. 11, May 1998.

“Play of light opens a new window into the body.” By Gary Taubes, Science, p. 1991, vol. 276, June 27, 1997.

“Spectroscopy and imaging with diffusing light.” By Arjun Yodh and Britton Chance, Physics Today, p. 34, vol. 48, March 1995.

“How to take a ‘visible x-ray.’” By Jeff Hecht, New Scientist, p. 18, December 1992.

“Brightness waves in cloudy liquids.” By Daniel Pendick, Science News, vol. 142, December 5, 1992.

“Finding may lead to the use of light instead of x-rays, in mammography.” By Jerry E. Bishop, Wall Street Journal, p. B4, November 2, 1992.

Diffuse Light for Research on Complex Fluids

“Multiple light scattering illuminates colloid interaction.” By Georg Maret, Physics World, p. 24, vol. 5, May 1992.

Entropy Forces and Self-Assembly in Solutions and Suspensions

“Another face of entropy: particles self-organize to make room for randomness.” By Peter Weiss, Science News, p. 108, vol. 154, August 15, 1998.

“Gentle force of entropy bridges disciplines.” By David Kestenbaum, Science, p. 1849, vol. 279, March 20, 1998.

“Disorderly conduct.” By Hans Christian Von Baeyer The Sciences, p. 15, May-June 1997.

“Entropy keeps small particles on the edge.” By D. Vergano, Science News, p. 182, vol. 150, September 21, 1996.

“Order out of disorder.” By Vanessa Houlder, Financial Times, p. 21, September 19, 1996.

“Getting order out of a mixture.” By Ivars Peterson, Science News, p. 223, vol. 145, April 2, 1994.

MRI Images of Foams

“Probing the interior of a coarsening foam.” By Ivars Peterson, Science News, p. 68, vol. 148, July 29, 1995.