Navigation Links
Videos extract mechanical properties of liquid-gel interfaces

Blood coursing through vessels, lubricated cartilage sliding against joints, ink jets splashing on paperliving and nonliving things abound with fluids meeting solids. However important these liquid/solid boundaries may be, conventional methods cannot measure basic mechanical properties of these interfaces in their natural environments. Now, researchers at the National Institute of Standards and Technology (NIST) and the University of Minnesota have demonstrated a video method that eventually may be able to make measurements on these types of biological and industrial systems.*

Optical microrheologyan emerging tool for studying flow in small samplesusually relies on heat to stir up motion. Analyzing this heat-induced movement can provide the information needed to determine important mechanical properties of fluids and the interfaces that fluids form with other materials. However, when strong flows overwhelm heat-based motion, this method isn't applicable.

Motivated by this, researchers developed a video method that can extract optically basic properties of the liquid/solid interface in strong flows. The solid material they chose was a gel, a substance that has both solid-like properties such as elasticity and liquid-like properties such as viscosity (resistance to flow).

In between a pair of centimeter-scale circular plates, the researchers deposited a gel of polydimethylsiloxane (a common material used in contact lenses and microfluidics devices). Pouring a liquid solution of polypropylene glycol on the gel, they then rotated the top plate to create forces at the liquid/gel interface. The results could be observed by tracking the motion of styrene beads in the gel.

The researchers discovered that the boundary between the liquid and gel became unstable in response to mechanical noise (irregularities in the motion of the plates). Such noise occurs in real-world physical systems. Surprisingly, a small amount of this mechanical noise produced a lot of motion at the fluid/gel interface. This motion provided so much useful information that the researchers could determine the gels mechanical propertiesnamely its viscoelasticityat the liquid/gel interface.

The encouraging results from this model system show that this new approach could potentially be applied to determining properties of many useful and important liquid/solid interfaces. The NIST/Minnesota approach has possible applications in areas as diverse as speech therapy where observing the flow of air over vocal cords could enable noninvasive measures of vocal tissue elasticity and help clinicians detect problems at an early stage. Also, this research may help clarify specific plastics manufacturing problems, such as shear banding, in which flow can separate a uniformly blended polymer undesirably into different components.


Contact: Ben Stein
National Institute of Standards and Technology (NIST)

Related biology news :

1. Bilberry extract -- can it help prevent certain cancers?
2. New mechanical insights into wound healing and scar tissue formation
3. Improving detection of nuclear smuggling goal of computer model of mechanical engineer
4. Weird water: Discovery challenges long-held beliefs about waters special properties
5. TRAP preserves genetic properties of popular geranium
Post Your Comments:
Related Image:
Videos extract mechanical properties of liquid-gel interfaces
(Date:9/10/2015)... , Sept. 10, 2015 Pursuant Health ... Wellness to create an interactive, image-based health risk ... and wellness kiosk.  The unique assessment quantifies user ... number that suggests an individual,s biological age based ... as measured by the kiosk. Comprised ...
(Date:9/9/2015)... VANCOUVER, British Columbia , Sept. 9, 2015 ... achieved numerous organizational and solution-based milestones, furthering the ... the perils of online fraud. NuData ... key in enhancing the company,s growth cycle. The ... machine learning to determine good user behavior from ...
(Date:9/8/2015)...  Affectiva, global leader in emotion-sensing and analytics, ... new data solution, and version 2.0 of its ... accurate and patented science, these new offerings provide ... industries such as market research, gaming, media and ... education, HR, automotive, robotics, healthcare and wearables. ...
Breaking Biology News(10 mins):
(Date:10/12/2015)... ... October 12, 2015 , ... LifeTrak , a ... of LifeTrak Zoom, the world’s first amphibious fitness tracker that seeks to meet the ... technology and accurate heart rate monitoring both in water and on land, ...
(Date:10/9/2015)... Governor Tom Wolf announced today that Adaptimmune ... T-cell receptor cancer immunotherapy treatments, will create at least ... Pennsylvania , and today,s announcement ... high-paying jobs will be created with this project," said ... sustained funding for the life science sector and increased ...
(Date:10/9/2015)... ... 2015 , ... Leading microbial genomics startup uBiome today launched the first-ever microbiome ... weight management and the microbiome. The study uses the ResearchKit framework, designed by Apple, ... , The uBiome app is available as a free download from the App Store. ...
(Date:10/8/2015)... , Oct. 8, 2015  ATCC, the premier global ... it has been selected by The Michael J. Fox ... lines to academic, pharmaceutical, and biotechnology organizations committed to ... the United States , and more than ... the United States , and more than ...
Breaking Biology Technology: