`
`STATEOFNEWYORK
`
`COUNTY OF TOMPKINS
`
`)
`)ss.
`)
`
`Pamela Stansbury being of full age and duly sworn, deposes and says as follows:
`
`I. I am an employee of the Cornell University Library, and specifically Library Technical
`Services, located at Cornell University, Ithaca, New York 14853. I have personal
`knowledge of the facts set forth below.
`
`2. I am the Administrative Supervisor in Library Technical Services, which maintains
`bibliographical and processing information for many historical documents. I have held
`such position since 1996.
`
`3. Included in the Library's historical collection are various publications. As part of that
`collection, the Library maintains custody of an original issue of the periodical Science,
`vol. 255 (24 January 1992) in which is the article, Optically transparent, electrically
`conductive composite medium I by S. Jin, T.H. Tie.fel, R. Wolfe, R. C. Sherwood, J.J.
`M ottine, Jr.
`
`4. Mr. Richard F. Moncrief requested information regarding an issue of the periodical
`Science, vol. 255 (24 January 1992) in which is the article, Optically transparent,
`electrically conductive composite medium I by S. Jin, T.H. Tie.fel, R. Wolfe, R. C.
`Sherwood, J.J. Mottine, Jr. a publication that we maintain in our collection -
`specifically when this item was first made publicly available by the Library. As best I
`can determine, the publication was publicly available at the Cornell University Library
`as of March 15. 1993. based the date stamp on the circulation slip.
`
`Samsung Exhibit 1019 p. 00001
`
`
`
`
`
`EXHIBIT A
`
`EXHIBIT A
`
`Samsung Exhibit 1019 p. 00002
`
`
`
`NY 14853
`
`ITHACA
`CORNELL l.tUVERSITY
`RH 110 OLIN LBRY 1 45079
`SERIALS DEPT LIBRARIES
`13
`00001814904AS 1Z./11/CJZN0492
`
`••*--••••••••••••••••••••• 5-DIGIT 14853
`
`Samsung Exhibit 1019 p. 00003
`
`
`
`AMERICAN
`AsSOCIATION FOR 1HE
`Aov AN CEMENT OF
`SCIENCE
`
`I )
`
`.
`c•r .... pc'f'IJ \ c • ....
`
`• CIENCE
`
`ISSN 0036-8075
`24 }ANUARY 1992
`VOLUME 255
`NUMBER 5043
`
`379 This Week. in Science
`
`381 Biotechnology in a Global Economy
`
`382 Patriot's Success Rate: R. A. SKELLY; E. MARSHALL • NSF-Funded Research
`Centers: H. K. BIRNBAUM • Air Pollution and Mortality: G. D. THURSTON AND
`H. 0ZKAYNAK
`
`391 Over and out for Bell Labs radio astronomy; a boost for teraflop computing; etc.
`
`392 The Case of the Florida Dentist • .Trying to Pin Down an· Ever-Changing Virus
`395 A Grim Exorcism at Leipzig University
`396 Coping With an "Embarrassment of Riches"
`398 Yale Plan Draws Faculty Fire
`Stanford and MIT in the Dock?
`
`399 Homeobox Genes Go Evolutionary.
`401 Jawing With Our Georgian Ancestors
`402 A Successful Forecast of an El Nifio Winter
`403 Knotty Problems-and Real-World Solutions
`404 Variable Stars Pulse in a New Light
`405 Pop! Goes the Pulsar Planet
`406 B~ngs: NSF Bombs in Ice Capade • FWS Ruffles Ornithologist's Feathers •
`Viral Tall Tale? • Recession Proof • Revival for Ivory Poaching • Science Role
`Model
`
`410 Potocytosis: Sequestration and Transport of Small Molecules by Caveolae:
`R. G. w. ANDERSON, B. A. KAMEN, K. G. ROTHBERG, S. W. LACEY
`411 Superantigens and Endogenous Retroviruses: A Conjluence of Puzzles:
`J.M.CoFFIN
`
`419 Information Processing in the Primate Visual System: An Integrated Systems
`Perspective: D. C. VAN EssEN, C. H. ANDERSON, D. J. FELLEMAN
`423 Climate Forcing by Anthropogenic Aerosols: R. J. CHARLSON, S. E. ScHWARTZ,
`J. M. HALES, R. D. CESS, J. A. CoAKLEY, }R., J. E. HANSEN, D. J. HOFMANN
`430 Addictive Drugs: The Cigarette Experience: T. C. ScHELLING
`
`434 Widespread Dispersion of Neuronal Clones Across Functional Regions of the
`Cer(!bral Cortex: C. WALSH AND C. L. CEPKO
`
`•
`
`•
`
`SCIENCE (ISSN 0036-8075) Ia published weekly on Friday, except the last week in December, by the American
`Aaaoc:latlon for the Advancement of Science, 1333 H Street, NW, Washington, DC 20005. Second-class postage
`(publication No. 484460) paid at Washington, DC, and additional mailing offices. Copyright © 1992 by the American
`· Association for the Advancement of Science. The title SCIENCE is a registered trademark of the AAAS. Domestic
`individual membership and subscription (51 issues): $87 ($47 allocated to subscription) . Domestic institutional
`subscription (51 issues) : $195. Foreign postage extra: Mexico, Caribbean (surface mail) $50; Other countries (air assist
`delivery) $95. First class, airmail, student and emeritus rates on request. Canadian rates with GST available upon
`request, GST #1254 88122. C"'nge of address: allow 6 weeks, giving old and new addresses and 11 -digit account
`number. P~: Send change of address to Science, P.O. Box 2033, Marion. OH 43305-2033. Single copy
`..... : $6.00 per issue prepaid includes surface postage; Guide to Biotechnology Products and Instruments, $20. Bulk
`rates on request. Authorization to photocopy material for internal or personal use under circumstances not falling
`within the fair use provisions of the Copyright Act is granted by AAAS to libraries and other users registered with the
`Copyright Clearance Center (CCC) Transactional Reporting Service, provided that the base fee of $1 per copy plus $0.10
`per page is paid directly to CCC, 27 Congress Street, Salem, Massachusetts 01970. The identification code for Science is
`0036-8075183 $1 + .10. Science is indexed in the Reader' Guide to Periodical Uterature and in several specialized
`Indexes .
`The American Association for the Advancement of Science was founded in 1848 and incorporated in 1874. Its objectives
`are to further the WOik of scientis1S. to facilitate cooperation among them, to foster scientific freedom and responsibility, to
`Improve the efectlveness of science in the promotion of human welfare, to advance education in science, and to increase
`public understanding and appreciation of the importance and promise of the methods of science in human progress.
`
`376
`
`SCIENCE, VOL. 255
`
`Samsung Exhibit 1019 p. 00004
`
`
`
`COVER Three-dimensional reconstructions of the cerebral cortex of a rat, viewed
`from behind. Colored symbols indicate retrovirally labeled neurons that form five
`clones. The three orange cells and the three green cells represent two widely
`dispersed neuronal clones, both extending over large cortical distances. See page
`434. [Photograph by C. Walsh]
`
`441 The Widespread Distribution of a Novel Silica Polymorph in Microcrystalline
`Quartz Varieties: P. ]. HEANEY AND]. E. PosT
`443 Shocked Quartz at the Triassic-Jurassic Boundary in Italy: D . M. BICE,
`C. R. NEWTON, S. McCAULEY, P. W. REINERs, C. A. Mc RoBERTS
`446 Optically Transparent, Electrically Conductive Composite Medium: S. ]IN,
`T. H. TIEFEL, R. WoLFE, R. C. SHERwooD, J. J. MorriNE, ]R.
`448 Sporogonic Development ofa Malaria Parasite in Vitro: A. W ARBURG AND
`L. H. MILLER .
`450 Polymerase II Promoter Activation: Closed Complex Formation and ATP-Driven
`Start Site Opening: W. WANG, M. CAREY, J.D. GRALLA
`453 DNA Binding Activity of Recombinant SRY from Normal Males and XY Females:
`v. R. HARLEY, D. I. JACKSON, P. J. HEXTALL, J. R. HAWKINS, G. D. BERKOVITZ)
`S. SocKANATHAN, R. LovELL-BADGE, P. N. GooDFELLow
`456 Protection of Macaques Against SIV Infection by Subunit Vaccines of SIV
`Envelope Glycoprotein gpl60: S.-L. Hu, K. ABRAMs, G. N . BARBER, P. MoRAN,
`J. M. ZARLiNG, A. J. LANGLOIS, L. KULLER, w. R. MORTON, R. E. BENVENISTE
`459 Modulation of Activity of the Promoter of the Human MDRl Gene by Ras and
`p53: K.-V. CHIN, K. UEDA, I. PASTAN, M. M. GOTTESMAN
`462- GnRH-Induced Ca2 + Oscillations and Rhythmic Hyperpolarizations of Pituitary
`Gonadotropes: A. TsE AND B. HILLE
`464 Predicted Structural Similarities of the DNA Binding Domains of c-Myc and
`Endonuclease Eco RI: T. D. HALAZONETIS ANP A. N. KANDiL
`467 Aromatase Enzyme Activity and Sex Determination in Chickens: A. ELBRECHT
`AND R. G. SMITH
`470 High Probability Opening ofNMDA Receptor Channels by L-Glutamate:
`c. E. ]AHR
`472 Axon Guidance by Gradients of a Target-Derived Compone.nt: H. BAIER AND
`F. BONHOEFFER
`
`477 To Witness and Heal: What Science Can Do to Respond to Human Rights Abuse
`• Congress Boosts Funding for Science • AAAS Fellow Nominations • 1992
`AAAS Dues !I AAAS Award Winners
`
`480 Free To Be Foolish, reviewed by R. BAYER ·• Secret Agenda, A. BEYERCHEN •
`Some Other Books of Interest • Vignettes: Earth Health • Books Received
`
`484 Ultraviolet Cross-Linker • NMR Spectrometer • Miniblotter • Surface Protector •
`Protein Sequencer • Low Profile Refrigerated Circulator • Particle Delivery
`System • Literature
`
`Editorial Board
`
`Charles J. Arntzen
`Elizabeth E. Bailey
`David Baltimore
`William F. Brinkman
`E. Margaret Burbidge
`Pierre-Gilles de Gennes
`Joseph L. Goldstein
`Mary L. Good
`Harry B. Gray
`John J . Hopfield
`F. Clark Howell
`Paul A. Marks
`Yasutomi Nishizuka
`Helen M. Ranney
`Robert M. Solow
`Edward C. Stone
`James D. Watson
`
`Board of Reviewing
`Editors
`
`John Abelson
`Frederick W. Alt
`Don L. Anderson ·
`Stephen J. Benkovic
`David E. Bloom
`Floyd E. Bloom
`Henry A. Bourne
`James J. Bull
`Kathryn Calame
`Charles R. Cantor
`C. Thomas Caskey
`Dennis W. Choi
`John M. Coffin
`Bruce F. Eldridge
`Paul T. Englund
`Fredric S. Fay
`Douglas T. Fearon
`
`Harry A. Fozzard
`Victor A. Fuchs
`Theodore H. Geballe
`Margaret J. Geller
`John C. Gerhart
`Roger I. M. Glass
`Stephen P .. Goff
`Corey S. Goodman
`Stephen J. Gould
`Ira Herskowitz
`Eric F. Johnson
`Stephen M. Kosslyn
`Konrad B. Krauskopf .
`Michael LaBarbera
`Charles S. Levings Ill
`Harvey F. Lodish
`Richard Losick
`Anthony A. Means
`Mortimer Mishkin
`. Roger A. Nicoll
`
`William H. Orme.Johnson Ill
`Stuart L. Pimm
`Yeshayau Pocker
`Dennis A. Powers
`Ralph S. Quatrano
`Erkki Ruoslahti
`Ronald H. Schwartz
`Terrence J. Sejnowski
`Thomas A. Steitz
`Richard F. Thompson
`Robert T. N. Tjian
`Emil A. Unanue
`Geerat J. Vermeij
`Bert Vogelstein
`Harold Weintraub
`Zena Werb
`George M: Whitesides
`Owen N. Witte
`William B. Wood
`Keith Yamamoto
`
`TABLE OF CONTENTS
`
`377
`
`Report~
`
`Inside AAAS
`
`Book Revie\vs
`
`Products & Materials
`
`111rd of Directors
`
`lllald N. Langenberg
`Jtiring President,
`rrairman
`oo M. Lederman
`'8Sident
`
`Sherwood Rowland
`esident-elect
`
`Mary Ellen Avery
`Francisco J. Ayala
`Eugene H. Cota-Robles
`Robert A. Frosch.
`Joseph G. Gavin, Jr.
`Florence P. Haseltine
`Jean'ne M. Shreeve
`Warren M. Washington
`
`William T. Golden
`Treasurer
`
`Richard S. Nicholson
`Executive Officer
`
`~JANUARY 1992
`
`Samsung Exhibit 1019 p. 00005
`
`
`
`searched for shocked quartz (see Fig. 1).
`The occurrence of what we interpret to be
`shocked quartz in several shale beds leads us
`to suggest that multiple impacts occurred in
`the latest Triassic, one of which coincided
`with a locally, and perhaps globally signifi(cid:173)
`cant extinction at the T-J boundary. The
`abrupt disappearance of the dominant Rhae(cid:173)
`tavicula fauna immediately below a shale
`containing shocked quartz, followed by an
`initially barren wne just above the boundary
`layer is consistent with the interpretation
`that the extinction was caused by environ(cid:173)
`mental stresses resulting from an impact
`event. The lower two shale layers containing
`shocked quartz are in a part of the section
`where fossils are scarce (Fig. 1); thus, it is
`difficult to establish whether there were any
`faunal changes immediately following depo(cid:173)
`sition of these shales, although Triassic
`benthic forams are found below and above
`these two lower shale beds.
`·
`Although it is possible that reworking of
`one impact ejecta layer, or normal fluvial
`transport from a source region with an older
`impact structure could account for the oc(cid:173)
`currence of shocked quartz in three layers,
`the angularity of the shocked quartz in
`contrast to the roundness of other sand
`grains and the occurrence of the shocked
`qdar:tz in three distinct layers are more con(cid:173)
`sistent with the interpretation of a series of
`impact events. Studies of the same interval
`from other sites are required to test the
`hypothesis of multiple impact events and an
`associated global extinction at the T-J
`boundary. Badjukov et al. (28) reported that
`shocked quartz was present in multiple lev(cid:173)
`els at the T-J boundary at the Kendelbach
`section in Austria, but Hallam (9) was un(cid:173)
`able to reproduce this finding.
`If the multiple-impact hypothesis is cor(cid:173)
`rect, then the events surrounding the T-J
`boundary would appear to .fit the model of a
`comet shower proposed by Hut et al. (29),
`in which a perturbation of the Oort cloud
`results in multiple impactS over a relatively
`short period of time; an instantaneous per(cid:173)
`turbation is expected to produce a number
`of impacts, 75% of which should occur
`within the first 0.9 million years. It is diffi(cid:173)
`cult to estimate confidently the titne spanned
`by the three shocked quartz·bearing shales,
`but there are at least 250m of Norian and
`Rhaetian beds in the ll Fiume gorge, repre(cid:173)
`senting about 15 million years. The result(cid:173)
`ing average rate of accumulation suggests
`that the beds A to C may span about
`150,000 years, well within the expected
`time of a comet shower (29) ~
`At present, there are no good candidate
`impact structures for the shocked quartz
`found in the Corfino section. The Mani(cid:173)
`couagan impact structure in Quebec has
`
`been dated at 214 ± S million years ago
`(Ma) (30) and would appear to be unrelated
`to the T-J boundary on the basis of a r~ent
`date of 204 ± 4 Ma for the boundary in the
`Newark Basin (31)'. Several smaller impact
`stnictures have dates that overlap the age for
`the T-J boundary (32), but none can be
`implicated with any confidence, iri consider(cid:173)
`arion of the large errors associated with
`these ages.
`
`REFERENCES AND NOTES
`l. D. M. Raup and ]. ]. Sepkoski, Science 215, 1501
`(1982).
`2. --·ibid. 231, 833 (1986) .
`3. P. Olsen and H.· D. Sues, in The &ginningofthi!Age
`of the Dinosaurs, K. Padian, Ed. (Cambridge Univ.
`Press, Cambridge, 1986}, pp. 321-351.
`4. P. Olsen, N.H. Shubin, M. H. Anders, Science 237,
`1025 (I987).
`5. M. r Benton, Nature 321, 857 (I986).
`6. _ , in Extirtction Events in &rth-History, E. G.
`Kauffinan and 0. H. WaJ4ser, Eds. (Ltct. Notes
`&rth Sci. 30, Springer Verlag, New York, 1990),
`pp. 239.
`7. S. Powell, Ceo/. Soc. Am. Absir. Progr. 22, 355
`(1990).
`8. A. Hallam, Pakogeogr. Paleoclimatol. Pakoecol. 35, I
`(1981).
`9. __ , Geol. Soc. Am. Spec. Pap. 247, 577 (1990).
`10. }. ]. Sepkoski, ibid. 190, 283 (I982).
`Il. G. D. Stanley, Palaios 3, I70 (I988).
`I2. J. Wiedmann, Bioi. Rev. 48, 159 (1973).
`I3. L. W. Alvarez, W. Alvarez, F. Asaro, H. V. Michel,
`Science 208, 109S (1980).
`14. W. Alvarez et al., ibid. 223, 1135 (1984).
`1S. W. Alvarez, Eos 71, 1424 (1990).
`16. A. R. Hildebrand and W. V. Boynton, ibid., p.
`1424.
`17. D. J. McLaren, and W. D. Goodfellow, Annu. Rev.
`Earth Planet. Sci. 18, 123 (1990).
`
`18. G. Ciarapica, S. Cirilli, L. Passcri, Mem. Soc. Geol.
`1141. U, ISS (I982).
`19. M. Fazzouli, E. Fois, A. Turi, Riv. !tal. Pakontol.
`Strat. 94, S61 (1988). This assignment is based on
`the widespread occurrence of several Hettangian
`species of the foraminifer Turrispirillina.
`20. G. Ciarapica and L. Zaninetti, Rev. Paleobiol. 1, 165
`identifications
`(I982) . Preliminary foraminiferal
`were made based on the nomenclature used by
`Ciarapica and colleagues.
`-
`21. G. Ciarapica, S. Cirilli, L. Passeri, E. Tincianti, ibid.
`6, 341 (1987).
`22. ]. S. Alexopoulos, R. A. F. Grieve, P. B. RobertsOn,
`Geology 16, 796 (1988).
`23. B. F. Bohor, E. E. Foord, P. ]. Modreski, D. M.
`Triplehorn, Science 224, 867 (1984).
`24. B. F. Bohor, P. ]. Modreski, E. E. Foord, ibid. 236,
`705 (1987).
`.
`2S. G. A. lzett, Geol. Soc. Am. Spec. Pap. 249, I
`(1990).
`. 26. ]. S. Alexopoulos, R. A. F. Grieve, P. B. RobertsOn,
`Geology 17, 478 (1989).
`27. W. V. Engelhardt and W. Bertsch, Contrib. Mineral.
`Petrol. 20, 203 (1969).
`28. D. D. Badjukov, H. Lobitzcr, M.A. Nazarov, Lunar
`Planet. Sci. XVIII, 38 (1987).
`.
`29. J>. Hut et al., Nature 329, 118 (1987).
`30. B. Jahn, R. }. Floran, C. H. Simmonds, ]. Geophys.
`Res. 83, 2799 (I979).
`31. G. R. Dunning and J.P. Hodych, Geology 18, 795
`(I990).
`.
`32. R. A. F. Grieve, Annu. Rev. Barth Planet. Sci. 215,
`24S (1987).
`33. Supported by PetrOleum Research Fund grant 227~
`GB2, theW. Keck Foundation, and the Pew Charitable
`Trusts (DM.R, S.M., and P.W.R.), National Science
`Foundation grant EAR-90I6704
`(C.R.N. and
`C.A.M.), and a grant from the Vice President for
`Research, Syracuse Univet"Sity (C.R.N. and C.AM.).
`We thank W. Alvarez, S. Cirilli, G. Ciarapica, M.
`Fazzuoli, R. A. F. Grieve, A. Hallam, L. Passeri, P. B.
`Robertson, G. A. Izett, ]. L. Macalady, and A. Mon·
`tanari for help and comments.
`
`.
`
`24 Jtme 1991; accepted 15 October 1991
`
`Optically Transparent, Electrically Conductive
`Composite Medium
`s. JIN, T. H. TrnFEL, R. WOLFE, R. c. SHERWOOD, J. J. MOTIINE, JR.
`
`The development of an optically transparent yet electrically conductive material made
`with a composite structure having preferentially arranged conductive paths is de(cid:173)
`scribed. The medium contains many vertically aligned but laterally isolated chains of
`ferromagnetic spheres dispersed in a sheet of transparent polymer. The sheet material ·
`transmits more than 90 percent of the incident light and is highly conductive only in the
`thickness direction. When suitably modified, the material exhibits on-off electrical
`switchability at a certain threshold pressure. These characteristics confer potential
`usefulness for visual communication devices such as write pads or touch-sensitive screens.
`
`O PTICALLY TRANSPARENT BUT ELEC(cid:173)
`
`trically conductive materials are
`useful for a variety of visual com(cid:173)
`munication, sensor, or electronic device ap(cid:173)
`plications. Transparent materials are in gen(cid:173)
`eral electrical insulators or high-resistivity
`
`S. Jin, T. H. Tiefel, R .. Wolfe, R. c: Sherwood, AT&T
`Bell Laboratories, Murray Hill, NJ 07974.
`J. ]. Mottine, Jr., AT&T Technologies, Omaha, NE
`68137.
`
`semiconductors because they have very low
`mobile charge carriers. Although some com(cid:173)
`posite materials [such as a glass coated with
`thin transparent metal or indium-tin oxide
`(ITO) coating] have both transparency and
`electrical conductivity, they exhibit only pla(cid:173)
`nar conductivity along the surface, and that
`with relatively high electrical resistivity. A
`tranSparent medium with high, through-the(cid:173)
`thickness conductivity is potentially usefuJ for
`a variecy of device applications such as write
`
`SCIENCE, VOL. 2SS
`
`Samsung Exhibit 1019 p. 00006
`
`
`
`anisotropic. The transparency along the ver(cid:173)
`tical (z) direction is high (with high trans(cid:173)
`mittance if the density of the columns is kept
`below a few percent by volume) but is lower
`in the horizontal (x-y) direction because of
`increased light blockage and scattering by
`the columns. The material is electrically con(cid:173)
`ductive only in the z direction (along the
`chains of spheres) while insulating in the x-y
`direction. Such anisotropies are useful ma(cid:173)
`terial characteristics that could be exploited
`for many device applications.
`Approximately 0.5 to 2.0% by volume of
`Ni spheres with an average diameter of -20
`~m and an Au or Ag coating -1000 A thick
`(for improved conductivity and corrosion
`resistance) was thoroughly mixed with op(cid:173)
`tically . transparent, uncured silicone elas(cid:173)
`tomer (RTV 615, General Electric Compa(cid:173)
`ny; viscosity, -40 poises). The mixture was
`spread on a flat glass substrate and a doctor
`blade was used to form a thin layer -150
`-~m thick; then it was heat-cured (120°C for
`15 min) in the presence of a vertical mag(cid:173)
`netic field of -600 Oe. The cured sheet was
`peeled off the substrate and tested for optical
`and electrical properties.
`Shown in Fig. 2 are typical microstruc(cid:173)
`tures of the material. Figure 2A reveals that
`the columns are reasonably well separated
`and spaced from each other. Most of the
`columns extend
`throughout
`the whole
`thickness (Fig. 2B). Using. a structural mod(cid:173)
`el that assumes a perfect triangular arrange(cid:173)
`ment (with sixfold symmetry) of vertical
`columns, we can estimate the average inter-
`·columnar spacing (Y) and the number of
`columns per unit area (N) by the following
`equations:
`
`Y = (D2/l.65 x) 112
`(1)
`N = 6x/-rrD2
`(2)
`where D is the particle diameter and x is the
`volume fraction of the particles in the com(cid:173)
`posite. For D. = 20 ~m and x = 0.0075, Y
`is calculated to be -180 J.Lm and N is -56
`columns per 1.25 by 1.25 mm2 area, wh\ch
`agrees well with the experimental values
`obtained from the microstruq:ure.
`Owing to the vertical arrangement of the
`particles, the composite material allows easy
`light transmission along the z direction.
`Shown in Fig. 3A are the z-direction light
`transmittance and absorbance data in the
`visible light spectrum (400 to 800 run) as a
`function of the volume percent of Ni parti(cid:173)
`cles. The transmittance is defined as the inten(cid:173)
`sity ratio of transmitted versus incident light
`(1!10 x 100%). ~e absorbmce represents
`the amount of light absorbed by the medium
`and is expressed as - -log (1/10 ) . The data
`have been calibrated against a standard sam(cid:173)
`ple containing no Ni particles in order to
`minimize the effectS of surface reflections.
`
`Substrate
`Fig. 1. Magnetic poles and interactions of vertical
`columns of spheres in a viscous medium.
`
`pads, touch-sensitive screens, sensors, and
`alann devices. In this report we describe the
`development of such a medium with desirable
`optical and electrical characteristics.
`In order to create a transparent sheet with
`vertical conducting paths, we utilized a mag(cid:173)
`netic field alignment of conductive ferromag(cid:173)
`netic particles in a transparent matrix material
`along the direction of intended light trans(cid:173)
`mission. When ferromagnetic spheres ran(cid:173)
`domly dispersed in a viscous medium are
`subjected to a unidirectional magnetic field,
`they move and align themselves jnto a chain
`configuration to minimize the magnetostatic
`energy. Therefore, if a v~rtical field of suitable
`intensity is applied to a thin layer of viscous
`medium containing magnetic particles, paral(cid:173)
`lel, vertically arranged columns (chains _of
`spheres) extending through the thickness of
`the matrix are formed (1). The resultant mag(cid:173)
`netic dipoles in the neighboring columns
`(Fig. 1) repel each other, thus positioning the
`columns toward an equilibrium spacing. The
`surface tension of the viscous medium pre·
`vents the undesirable overgrowth of columns
`beyond the thickness of the layer. The matrix
`material (such as glass, silicone elastomer,
`epoxy resin, and so forth) can then be cured
`to retain the magnetically aligned conductor
`structure.
`Such a composite structure results in a
`material that is both optically and electrically
`
`Fig. 2. Micrographs showing (A) top and (B)
`cross-sectional view of the transparent composite
`medium.
`
`14 JANUARY 1992
`
`The light transmittance decreases with
`increasing number ofNi particles (Fig. 3A).
`About 30% loss in transmittance is observed
`with a Ni concentration of-2% by volume
`(corresponding to approximately 2% in
`cross-sectional area in the z direction). It is
`likely that scattering of light caused by the
`rough top surface and by an altered refrac(cid:173)
`tive index in the strained polymer material
`near the N i particles is responsible for the
`loss in transmittance. Indeed, the transmit(cid:173)
`tance is significantly improved if the top
`surface of the comp6site is made smoother
`(from -70 to -87% transmittance).
`If the volume percent of Ni is kept rela(cid:173)
`tively low, for example, below 0.75%, excel(cid:173)
`lent light transmission (in excess of 90%) is
`- achieved. (The 0.75% Ni sample still pro(cid:173)
`vides excellent z-direction conductivity with
`an average through-resistance of less than 1
`ohm for 1.25 by 1.25 mm2 area.) Such a
`high transmittance is essential for clear visi(cid:173)
`bility of underlying word or graphic infor(cid:173)
`mation in touch-sensitive screen or see(cid:173)
`through _write pad applications. The light
`transmittance of the material shows essen(cid:173)
`tially no dependence ~n wavelength within
`the visible light range.
`For visual communication devices such as
`touch-sensitive screen or transparent write
`pad, the light transmission along the off-axis
`orientations is also important as the screen is
`often viewed by the user at some angle away
`from the perpendicular. axis. Shown in Fig.
`
`g
`~ 80 -
`)(
`..p
`~ 60-
`8 c
`~ 40 r-
`E
`(I) c
`as
`~
`
`20 r-
`
`100~--------------------·
`'A,'"'o
`0
`.............
`/' - 0.20 _;?
`__._ '"""o.,
`....... ...;
`,if
`-
`a-...... "~--
`"
`~/
`"" ,"-
`/"
`,""
`,"
`," "
`,'"
`"
`0 ,-"
`0
`
`!
`! c
`- 0.10 .e
`i
`~
`
`I
`I
`I
`I
`2.0
`1.5
`0.5
`1.0
`Nl (volume percent)'
`
`0
`
`- 0.50
`
`I
`
`.
`
`. :
`
`-
`
`B
`100 1-
`--._
`--o----o----... <1
`~---o--
`~
`~ 80 -
`~-·-------\
`8
`! 60 I-
`E
`. 1.5% ~i_... ... c.
`~ 40 I-
`.,/
`~ ~---------
`-~_,.......
`0.75% Ni
`--6---~--~----::::___...
`I
`I
`I
`I
`I
`I
`.--
`~~~~--~--~--~--~~o
`0
`10
`20
`30
`40
`50
`60
`Angle (deg)
`Fig. 3. (A) Light transmittance and absorbance
`versus volume percent of Ni in the composite
`medium. (B) Transmittance versus off-axis angle
`for the composite medium.
`
`0.75% Ni
`l - 0.40
`.............
`8
`;-ca._
`c
`- 0.30 ~
`i
`"I;
`'·,- 0.20 ~
`
`1 So/c Ni
`- - ...... ...: .... 0
`............... /
`:.00..
`_,/ ............
`
`, /
`
`...
`
`- 0·10
`
`REPORTS ~7
`
`Samsung Exhibit 1019 p. 00007
`
`
`
`3B are the transmittance data as a function
`of off-axis angle. For the 0.75% Ni sample,
`the light transmittance remains nearly 90%
`even at an off-axis angle as much as 30° and
`decreases only slightly to -85% at 45°
`orientation. The angle dependence is slight(cid:173)
`ly more severe in the 1.5% Ni sample
`(which contains twice as many vertical col(cid:173)
`umns as the 0.75% Ni sample), as might be
`anticipated from a simple geometrical line(cid:173)
`of-sight consideration.
`We evaluated the electrical conductivity of
`the composite medium along the vertical
`direction (through resistance) by four point
`resistance measurement, using a constant de
`current of 10 rnA. The composite sheet was
`sandwiched between two circuit boards (the
`lower board contained multiple 1.25-mm(cid:173)
`wide conductor lines running in the x direc(cid:173)
`tion, whereas the upper board had one
`1.25-mm-wide conductor line running in
`they direction). A nominal pressure of 5 psi
`(0.035 MPa) was applied during the mea(cid:173)
`surement to ensure good contacts between
`the metal spheres. The average through(cid:173)
`resistance of the composite medium so mea(cid:173)
`sured was -370 milliohms per 1.25 by 1.25
`mm2 contact pad area. For the given sheet
`thickness of -:-150 f..Lm, this resistance value
`translates into an apparent z-direction resis(cid:173)
`tivity f -0.39 ohm-em for the composite
`material. Because there is only 0.75% by
`volume of the conductor present, the resis(cid:173)
`tivity of the column itself is much lower
`( -2900 microohm-cm).
`The electrical conductivity of the compos(cid:173)
`ite medium in the x-y direction was mea(cid:173)
`sured to be negligible, as might be expected
`ffom fh~ mi~r6nru~ft.irt. Th~ iH-phrnt rt ~
`tivity was > 109 ohm-em, a value repre(cid:173)
`sentative of the insulative polymer matrix.
`An optically transparent, z-direction con(cid:173)
`ductive medium such as described here may
`be useful as a pressure sensor for visual
`communication devices such as write pads
`or finger-touch-sensitive layers on display
`
`screens ( 2). The transparency of the pressure
`sensor is an advantage for tracing an under(cid:173)
`lying pattern such as a map or chart or for
`minimizing the loss of display quality under(cid:173)
`neath a touch-sensitive screen.
`In order to make the present composite
`medium more suitable for transparent write
`pad type applications, we have further mod(cid:173)
`ified the material to achieve electrical on-off
`switchability. A very thin layer ( -s· J.Lm) of
`silicone elastomer was spray-coated over the
`top surface of the cured composite material.
`We have discovered that this extra layer
`could serve as an insulating barrier at a low
`applied pressure such as that exerted by a
`hand resting on the write pad, but it allows
`z-direction electrical conduction above a
`certain threshold pressure, for example, as
`exerted by a tip of a writing stylus.
`The threshold pressure, which can be
`adjusted by controlling the barrier thickness,
`is in the range of10 to 50 psi (0.069 to 0.345
`MPa). Below this threshold, the through(cid:173)
`resistance for a 1.25 by 1.25 mm2 pad was
`greater than 20 megohms, whereas above the
`threshold the resistance was typically less than
`-0.8 ohm. The underlying mechanism for
`this switchability is not clearly understood.
`However, it is most likely caused by the upper
`end of the vertical columns (slightly protrud(cid:173)
`ing as shown in Figs. 1 and 2) puncturing
`through the insulating barrier layer above the
`threshold pressure and then retracting when
`th.e pressure is reduced.
`Schematically illustrated in Fig. 4 is an
`assembly constructed to demonstrate the
`feasibility of a write pad device that uses the
`composite medium containing -1% by vol-
`
`urne of the particles. The medium (15 em by
`15 em by 150 J.Lm) was sandwiched between
`two Mylar sheets ( -75 tJ.m thick) coated
`with ITO with the conductive side facing
`the composite medium.
`The total electrical resistance was 482 7
`ohms. It includes the resistance from one
`edge of the upper ITO layer to the location
`of the stylus 6 em away from the edge plus
`the z-direction through-resistance in the
`composite medium plus the resistance from
`the stylus to the same-side edge of the lower
`ITO layer (Fig. 4). (A normal writing pres(cid:173)
`sure by the tip of a pencil is estimated to be
`-100 psi, which is over the threshold value
`of 10 to 50 psi.) Because the through(cid:173)
`resistance in the medium contributes not
`more than -1 ohm to the combined resis(cid:173)
`tance, the above resistance value. represents
`primarily that of the ITO layers. As the
`location of the stylus changes, the measured
`resistance also varies, allowing the x-y coor(cid:173)
`dinate positions to be sensed by a number of
`different schemes (3, 4). The total resistance
`for the case of a hand resting on the pad (-2
`psi pressure, well below the threshold) . was.
`greater than 20 megohms, thus · causing no.
`interference with the position sensing.
`
`REFERENCES AND NOTES
`
`l. S. ]in et al., ]. Appl. Phys. 64, 6008 (1988).
`2. S. ]in,].]. Mottine, R. C. Sherwood, T. H. Tiefel,
`U_.S. Patent 4,664,101 (17 February 1987).
`3. D.]. Grover, Displays 1 (no. 2), 83 (July 1979).
`4. G. ]. Ritchie and ]. A Turner, Int. ]. Man-Mach.
`Stud. 7, 639 (1975).
`5. We thank G. L. Miller, R. A. Boie, and L. Shepherd
`for stimulating discussions.
`
`11 September 1991; accepted 13 November 1991
`
`Sporogonic ·Development of a
`Malaria Parasite in Vitro
`ALaN W ARBURG* AND LOUIS H. MILLER
`
`The sporogonic- cycle of the avian malaria parasite Plasmodium gallinaceum was
`completed in vitro. Ookinetes (motile iygotes) were seeded onto a murine basement
`membrane-:-like gel (Matrigel) in coculture with Drosophila melanogaster cells (Schnei(cid:173)
`der's L2). Transformation into ooeysts. as well as subsequent growth and differentia(cid:173)
`tion were observed in parasites .attached to Matrigel .and depended Qn the presence of
`L2 cells. Sporozoites were first observed on day 10 in cultUre. Specific circwnsporo(cid:173)
`zoite protein antigenicity was identified in mature oocysts and in sporozoites. It is now
`· possible to fotlow the entire life cycle of Pla1modium in vitro.
`
`SIGNIFICANT PROGRESS HAS BEEN
`
`made in the culrure of the intracellular
`vertebrate stages of malaria parasites.
`The blood stages of many species multiply
`readily in continuous culr:ure ( 1), and the
`exoerythrocytic cycle can also be completed
`in appropriate cells in vitro (2). These
`
`achievements stand in marked contrast to
`the limited success in the cultivation of the
`
`Malaria Section, Laboratory of Parasitic Diseases, Build(cid:173)
`ing 4, Room 126, National Instirute of Allergy and
`Infectious Diseases, National Instirutes of Health, Be(cid:173)
`thesda, MD 20892.
`
`*To whom correspondence should be addressed.
`
`SCIENCE, VOL. 255
`
`Transparent
`composite
`Fig. 4. Schematic illustration of an exemplary
`write pad assembly usi