A Feb. 18, 2014 news item on Azonano highlights a presentation about living liquid crystals that was given at the 58th annual Biophysical Society Meeting in San Francisco on Feb. 17, 2014,
Plop living, swimming bacteria into a novel water-based, nontoxic liquid crystal and a new physics takes over. The dynamic interaction of the bacteria with the liquid crystal creates a novel form of soft matter: living liquid crystal.
The new type of active material, which holds promise for improving the early detection of diseases, was developed by a research collaboration based at Ohio’s Kent State University and Illinois’ Argonne National Laboratory. The team will present their work at the 58th annual Biophysical Society Meeting, held in San Francisco, Feb.15-19 .
ScienceDaily featured the story in a Feb. 17, 2014 news item,
As a biomechanical hybrid, living liquid crystal moves and reshapes itself in response to external stimuli. It also stores energy just as living organisms do to drive its internal motion. And it possesses highly desirable optical properties. In a living liquid crystal system, with the aid of a simple polarizing microscope, you can see with unusual clarity the wake-like trail stimulated by the rotation of bacterial flagella just 24-nanometers thick, about 1/4000th the thickness of an average human hair.
You can also control and guide active movements of the bacteria by manipulating variables such as oxygen availability, temperature or surface alignment, thus introducing a new design concept for creating microfluidic biological sensors. Living liquid crystal provides a medium to amplify tiny reactions that occur at the micro- and nano-scales — where molecules and viruses interact — and to also easily optically detect and analyze these reactions. That suits living liquid crystal to making sensing devices that monitor biological processes such as cancer growth, or infection. Such microfluidic technology is of increasing importance to biomedical sensing as a means of detecting disease in its earliest stages when it is most treatable, and most cost-effectively managed.
Quotes from the lead researcher and presentation details can be found in the Feb. 17, 2013 news item on newswise.com,
“As far as we know, these things have never been done systematically as we did before in experimental physics,” explained Shuang Zhou, a Ph.D. candidate at Ohio’s Kent State University. He collaborated on the project with Oleg Lavrentovich of Kent State, Andrey Sokolov of Argonne National Laboratory, in Illinois, and Igor Aranson of Argonne National Laboratory and Northwestern University, in Evanston, Ill.
“There are many potential applications for this kind of new material, but some of the more immediate are new approaches to biomedical sensing design,” Zhou said. He likens the current investigation to the “first handful of gold scooped out of a just-opened treasure chest. There are many more things to be done.”
The presentation “Living Liquid Crystals” by Shuang Zhou, Andrey Sokolov, Oleg D. Lavrentovich and Igor S. Aranson will be at 1:45 p.m. on Monday, February 17, 2014 in Hall D in San Francisco’s Moscone Convention Center.
Here’s the presentation abstract (from the abstractsonline website),
Bio-mechanical hybrids are an emerging class of engineered composite soft materials with the ability to move and reconfigure their structure and properties in response to external stimuli. Similar to their biological counterparts, they can transduce energy stored in the environment to drive systematic movements. This functionality is critical for a variety of applications, from bioinspired micromachines and sensors to self-assembled microrobots. Here, by combining two seemingly incompatible concepts, living swimming bacteria and inanimate but orientationally ordered lyotropic liquid crystal, we conceive a fundamentally new class of matter – living liquid crystals (LLCs). LLCs can be actuated and controlled by the amount of oxygen available to bacteria, by concentration of ingredients or by the temperature. Our studies reveal a wealth of intriguing phenomena, caused primarily by the coupling between the activity-triggered flows and director reorientations. Among these are (a) coupling between the orientation and degree of order of LLC and the bacterial motion, (b) local nematic-isotropic phase transition caused by the bacteria-produced shear flows, (c) periodic stripe instabilities of the director in surface-anchored LLCs, (d) director pattern evolution into an array of disclinations with positive and negative topological charges as the surface anchoring is weakened or when the bacterial activity is enhanced; (e) direct optical visualization and quantitative characterization of microflows generated by the nanometers-thick bacterial flagella by the birefringent LLC medium. Our work suggests an unorthodox design concept of reconfigurable microfluidic chambers for control and manipulation of bacteria. Besides an obvious importance to active matter, our studies can result in valuable biosensing and biomedical applications.
The researchers associated with this work are,
Shuang Zhou, Andrey Sokolov, Oleg D. Lavrentovich, Igor S. Aranson
Their research has been published online by the Proceedings of the National Academy of Sciences (PNAS),
Living liquid crystals by Shuang Zhou, Andrey Sokolov, Oleg D. Lavrentovich, and Igor S. Aranson. PNAS approved December 12, 2013 (received for review November 22, 2013) doi: 10.1073/pnas.1321926111
This paper is behind a paywall but it can be accessed via the tabs seen directly after the publication history (approved … received …). You will see Abstract, Authors, … and two symbols signifying the formats in which the paper is available.