June, 2008
This month we will consider “what was new” at the SID conference in LA.
Well, for one thing, our conference center was next to the theater where the final “American Idol” was
taped. Walking to the conference on that day there were lots of cameras and lines of very well dressed
people that looked considerably less nerdy than us in the SID crowd.
A more technical note, three things stood out as somewhat new to me. These are not the result of careful
reflection however, but are just what I happened to notice. One thing was the emphasis on 3D. 3D is
not new at all, but the interest and emphasis on it was. There is particular interest in the 3D for movie
theaters. I suppose that as 3D material is generated for movies, we might expect home equipment that
could also show them, and this could drive a larger 3D display businesses. From a user viewpoint, 3D
technology still has a long way to go before it achieves its goal of a generating a virtual space, so this
could be an interesting area in the coming years.
Another new thing was the interest in liquid crystal devices called pico projectors. These are available,
for example, from Displaytech (http://www.aboutprojectors.com/news/2008/01/04/displaytech-displaysiview-pico-projector-at-ces-08/; http://www.displaytech.com/projection.html ; ) and 3M
(http://www.3m.com/mpro/technology.html ) The 3M unit is shown in the picture:
The main application for these is for PDA’s and cell phones where a larger image is desired.
The other new thing was the liquid crystal blue phase display shown by Samsung. The pictures below are
of the display and the sign below it.
Samsung did not say anything about this technology demonstration, beyond what is in the picture above.
The Blue phase is a liquid crystalline phase of highly chiral molecules that exists between the chiralnematic ( cholesteric ) and isotropic phases. While the cholesteric phase as a single helical axis, the blue
phase has a three dimensional array of helical axes. Why this could exist can be sort-of seen by
considering first a single chiral molecule represented by the vertical solid line in the two pictures below:
It can be seen that if neighboring molecules would like to twist relative to that center molecule, they
could do that (for example ) with the helical axis coming out of the paper (as on the left), or along a
horizontal axis (as on the right). If the 3D collection of molecules picks one axis, the twisting along the
other axis will be frustrated. So, what about a 3D collection of molecules where both of the twist axis
shown above exist at the same time? This is what happens in the blue phase. But there is no way to
have multiple axes and fill the space in a continuous manner. Peter Collings’ book “Liquid Crystals,
Natures Delicate Phase of Matter” (Princeton) gives an clear description of this phase, but without going
into the details there are two things that are characteristic of this phase. One is that it has a array of
defects that results from locations where the helical twisting is discontinuous. The spacing of these
defects can be on the order of the wavelength of visible light and can create a 3D Bragg reflector (or
photonic crystal). Related to this, the phase can have a blue color, (and therefore the name). The other
characteristic, is that while the phase is locally anisotropic, because of the tight multi-dimensional helix,
it is macroscopically isotropic.
The interesting part for electo-optical applications is that if an electric field is applied to the blue phase,
the director field can be distorted and the material exhibits macroscopic birefringence. This basic idea
then is to have in-plane electrodes to create an in-plane field to induce the birefringence. A display using
this could be considered to have at least two nice attributes. One is that the low field state is truly
isotropic, so if this is the black state it will be have an excellent viewing angle. Another is that due to the
large amount of internal distortion of the 3D structure of the phase, it will relax very quickly after a field
is applied, and that relaxation will be independent of the cell thickness.
But there are issues. One is that the naturally occurring blue phase only exists over a very narrow
temperature range, and another is that the voltage and cell thickness required to get a half wave
retardation can be large. The first problem has been solved by polymer stabilization of the phase. This
method is made clear in a paper “Large Electrooptic Kerr Effect in Polymer Stabilized Liquid Crystalline
Blue phases” by Y. Hisakado, H. Hikuchi, T. Nagamura, and T. Kajiyama in Advanced Materials,17,
No.1, January 6, 2005 page 96. But the other problem is not solved here. In this paper they give data
on a 25 micron thick device that has inter-digital electrodes with 50 micron gaps between them. If I have
done the math correctly…I come up with a requirement of over 300 volts needed to be applied to the
electrodes to achieve a half wave retardation from the cell. So, it looks to me (if any of the above relates
to the Samsung display) that Samsung has made some major advances in solving the high voltage
problem. I could be on completely track about this device, but if so…this work could lead to new display
modes that are very fast and have excellent viewing angle.
STAFFING
Bentley Wall has accepted a position with Dynamic Eye, and has already begun full time employment
there. However, he will continue to provide limited consulting services to the IPP in the future. This
means that ACF bonding and GCMS analysis will still be available through the LCDRF at the same high
level as in the past.
Also, Doug Bryant is at a training seminar (June 16 -20) related to our optical ellipsometer, so he will be
better able to answer any question you have about this powerful technique. And, he will be on vacation
July 7 -11.
NEWS
New on the IPP Web Site
Videos of recent seminars can be found in the members-only section of the web site (click the yellow
button at the bottom of the IPP home page). In the last issue of the IPP newsletter you were given a user
id and password.
We’ve recently posted the LCI Annual Report 2006-2007, which can be found at:
http://www.lci.kent.edu/ipp/07/lciconnection.htm
LCI News
Kent State Awarded More than $14 Million to Study Liquid Crystals and Soft Matter
On May 21, Kent State University announced that it will lead a partnership of eight northeast Ohio
entities in a $14.5 million Ohio Research Scholars Program project to establish a Research Cluster on
Surfaces in Advanced Materials. The new research center will be located at Kent State's Liquid Crystal
Institute.
Lieutenant Governor Lee Fisher, chair of the Ohio Third Frontier Commission, and Ohio Board of
Regents Chancellor Eric Fingerhut, announced the award this afternoon as a reaffirmation of Ohio’s
commitment to attracting world-class talent and better aligning Ohio’s research investments with
economic development.
The funding for the Kent State partnership was selected through a competitive proposal process on the
basis of how effectively it related to Ohio's targeted technology/research focus areas of advanced
materials; biosciences; instruments, controls, and electronics; information technology; and power and
propulsion.
The research venture will combine the scientific excellence in fundamental and applied research at Kent
State and Case Western Reserve University with innovative approaches to environmental technologies at
the Cleveland Botanical Garden and highly successful commercialization of new technologies at Ohiobased AlphaMicron, Inc., CoAdna Photonics, Inc., Kent Displays, Inc., Kent Optronics, Inc., and LXD,
Inc. The significant state investment is being made to ensure that Ohio retains its top international ranking
for liquid crystal technology, research, technology transfer and commercialization.
Kent State will receive two endowed Research Scholar positions and Case Western Reserve will receive
one.
The Ohio Research Scholars Program provides grants to strengthen and increase the number of clusters of
research excellence that are led by Ohio's academic institutions that support regional economic priorities.
The Ohio Research Scholars Program aims to achieve this through aggressive investment in the attraction
of senior research talent and related facilities and equipment, and promotion of unique collaborations
needed to build and sustain scientifically and commercially promising lines of research.
LCI Seminars:
June 11, 2008: Prof. Yuriy Reznikov, Institute of Physics, Kiev, Ukraine, "Ferroelectric colloids in
nematic liquid crystals".
LCI Hosts Three REU Undergraduates this Summer
Three CPIP Faculty members will be advising Summer REU (Research Experience for Undergraduates)
students from June 2 through August 8. Professor Antal Jakli is advising Saba Hamidi from South
Carolina State University; Professor Oleg Lavrentovich is advising Nara Lee from George Washington
University; and Professor Qi-Huo Wei is advising Hannah Ainsworth from Salem College (North
Carolina). The students receive a summer salary and free dorm room. They will attend weekly seminars
and cleanroom training. At the end of the term each student will give a research presentation.
The International Liquid Crystal Conference is June 29 – July 4 in Korea.
The LCI will be well represented at this conference giving a number of papers. If you think you might be
interested in anything presented at the conference, please go to : http://www.ilcc2008.org and have a
look at what will be presented. If you see a paper you are interested in, please let me know and I will try
to get additional information about it.
Please also let us know if you would like more detailed information about the SID Conference or any
activities at the LCI.
Phil Bos
pbos@lci.kent.edu
330-672-2511