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Nanotechnology, a science that manipulates materials with atomic or molecular precision, is regarded as the next basic technology to follow Information Technology and Biotechnology. Nanotechnology promises new solutions for many of society’s greatest technological needs, including sustainable energy sources, breakthroughs in medical diagnosis and therapy, rapid advances in information technology, and exciting new strategies for manufacturing. Nanotechnology is driving the fundamental research agenda in many areas of science and engineering, and is the focus of major new R & D funding from federal agencies and the private sector.

UT Austin has one of the largest and most successful research programs in nanotechnology world-wide. Over 450 researchers, in nine departments and 65 faculty research groups are working at the forefront of such exciting areas as nanoelectronics, nano biology and medicine, nano structured polymers, nanoparticle synthesis, nanotechnology for energy needs (e.g. for photovoltaics, fuel cells and catalysis), nano applications to spintronics and plasmonics, nano imprint lithography, nano tube research just to name a few of the main areas.


Becker, Michael F., Keto, John W., and Lee, Jaemyoung. "Laser-induced breakdown of soda-lime glass microspheres using Nd : YAG laser" Optics and Laser Technology. Jun 2007, Vol. 39, Issue 4, pp. 835-839.

The Nd:YAG laser-induced breakdown of 20 mu m glass microspheres was investigated using time-resolved optical shadow and Schlieren images. Time-resolved imaging showed the location of the initial breakdown and the shockwave motion over its first 400 mu m of expansion. Measured shockwave velocities were in the range of 1-10 km/s and showed a linear dependency on laser fluence within 30 ns. (c) 2006 Elsevier Ltd. All rights reserved.



Huang, Rui and Pang, Yaoyu. "Bifurcation of surface pattern in epitaxial thin films under anisotropic stresses" Journal of Applied Physics. Jan 15, 2007, Vol. 101, Issue 2.

Surface instability of epitaxial thin films leads to a variety of surface patterns. Anisotropy in surface and bulk properties has profound effects on the dynamics of pattern formation. In this paper,
we theoretically predict that under anisotropic mismatch stresses, a bifurcation of surface pattern occurs in addition to generic symmetry breaking from isotropic systems. Numerical simulations based on a nonlinear evolution equation demonstrate pattern selection at an early stage and nontrivial patterns for long-time evolution. (c) 2007 American Institute of Physics.



Liechti, K. M., Ravi-Chandar, K., Wang, M., and Xu, D. "On the development of a mesoscale friction tester" Experimental Mechanics. Feb 2007, Vol. 47, Issue 1, pp 123-131.

AB MEMS and NEMS devices typically have a large surface area to volume ratio. As a result, a major concern in the development of such devices is friction. Contact radii in MEMS and NEMS devices are expected to range from 10 (-8)< a < 10(-5) m. This regime, which generally lies
between the limits of single asperity and macroscopic contact, has yet to be explored because the apparati used to characterize friction at these limits do not operate in the range of forces appropriate to these length scales. A Mesoscale Friction Tester (MFT) with smooth probe tip
radii from 50 mu m to 50 mm and capable of applying forces ranging from 10 nN to 1 mN over contact radii from 10 nm to 10 mu m has been developed to address this need. With carefully planned experiments, this device has the potential to help answer unresolved questions
regarding friction mechanisms in the mesoscale range.



Fu, Y. -Z., Guiver, M. D., and Manthiram, A. "Blend membranes based on sulfonated poly(ether ether ketone) and polysulfone bearing benzimidazole side groups for DMFCs" Electrochemical and Solid State Letters. 2007, Vol. 10, Issue 4, pp B70-173.

Blend membranes consisting of sulfonated poly(ether ether ketone) (SPEEK), which is an acidic polymer, and polysulfone bearing benzimidazole side groups (PSf-BIm), which is a basic polymer, have been prepared with various PSf-BIm contents (0 - 10 wt%). The blend membranes have been characterized by ion exchange capacity, proton conductivity, liquid uptake, methanol permeability, and polarization measurements in direct methanol fuel cell (DMFC). The membranes with an optimum PSf-BIm content of similar to 8 wt% exhibit electrochemical performance in DMFC better than that of plain SPEEK membrane due to an enhancement in proton conductivity through acid-base interactions and lower methanol crossover. (c) 2007 The Electrochemical Society.



Bielawski, Christopher W. and Grubbs, Robert H. "Living ring-opening metathesis polymerization" Progress in Polymer Science. Jan 2007 Vol. 32, Issue 1, pp 1-29.

AB Since the discovery of olefin metathesis in the mid-1950s, there has been great interest in using this versatile reaction to synthesize macromolecular materials. More recently, living ring-opening metathesis polymerization (ROMP), a variation of the olefin metathesis reaction, has emerged as a particularly powerful method for synthesizing polymers with tunable sizes, shapes, and functions. The technique has found tremendous utility in preparing materials with interesting biological, electronic, and mechanical properties. This review covers the fundamental aspects of living ROMP and briefly traces its historical development from a catalyst-design perspective. Highlights from the recent literature are used to illustrate the utility of living ROMP in the preparation of macromolecular materials with advanced structures and functions. A discussion on the current status of state-of-the-art catalysts for use in living ROMP reactions as well as opportunities for the future concludes this review. (c) 2006 Elsevier Ltd. All rights reserved.



Kim, Do Hoon, Paul, D. R., and Shah, Rhutesh K. "Morphology and properties of nanocomposites formed from ethylene/methacrylic acid copolymers and organoclays" Polymer. Feb 9, 2007, Vol. 48, Issue 4, pp 1047 - 1057.

AB Nanocomposites were prepared by melt mixing ethylene/methacrylic acid copolymers and organoclays, which were compared to equivalent composites prepared from low-density polyethylene (LDPE) and a sodium ionomer of poly(ethylene-co-methacrylic acid). The effects of matrix modification and organoclay structure on the morphology and properties of these nanocomposites were evaluated using stress-strain analysis, wide-angle X-ray scattering (WAXS), and transmission electron microscopy coupled with particle analysis. With all four polymers, the
use of a two-tailed organoclay, M-2(HT)(2), led to the formation of more exfoliated nanocomposites than a one-tailed organoclay, M-3(HT)(1). Nanocomposites prepared from ethylene/methacrylic acid copolymers revealed better exfoliation compared to similar composites prepared from LDPE. It seems that the presence of relatively small quantities (1.3-3.1 mol%) of the polar methacrylic acid monomer aids in improving the organoclay exfoliation efficiency of these polymers. Nanocomposites prepared from the sodium ionomer of poly(ethylene-co-methacrylic acid) exhibited the highest levels of organoclay exfoliation compared to all other polymers examined in this
study. However, from the observations made in this study, it was not possible to determine conclusively the relative interaction of carboxyl acid groups versus the salt form with the organoclay and, thus, their influence on exfoliation; additional studies will be needed to reach a
conclusion on this important point. (c) 2007 Elsevier Ltd. All rights reserved.



Banerjee, S. K. and Gilbert, M. J. "Ballistic recovery in III-V nanowire transistors" Journal of Vacuum Science & Technology. Jan-Feb 2007, Vol. 25, Issue 1, pp 189-193.

AB In recent years, a great deal of attention has been focused on the development of quantum wire transistors as a means of extending Moore's law. Here the authors present results of fully three-dimensional, self-consistent quantum mechanical device simulations of InAs trigate
nanowire transistor. The effects of inelastic scattering have been included as real-space self-energy terms. They find that the position of dopant atoms in these devices can lead to a reduction in the amount of scattering the carriers experience. They find that the combination of deeply buried dopant atoms and the high energy localization of polar optical phonon processes allow devices to recover their ballistic behavior even in the presence of strong inelastic phonon processes. (c)
2007 American Vacuum Society.



Arifler, Dogu, de Veciana, Gustavo, and Evans, Brian L. "A factor analytic approach to inferring congestion sharing based on flow level measurements" IEEE-ACM Transactions on Networking. Feb 2007, Vol. 15, Issue 1, pp 67-79.

AB Internet traffic primarily consists of packets from elastic flows, i.e., Web transfers, file transfers,. and e-mail, whose transmissions are mediated via the Transmission Control Protocol (TCP). In this paper, we develop a methodology to process TCP flow measurements in order to analyze throughput correlations among TCP flow classes that can be used to infer congestion sharing in the Internet. The primary contributions of this paper are: 1) development of a technique for processing flow records suitable for inferring congested resource sharing; 2) evaluation of the use of factor analysis on processed flow records to explore which TCP flow classes might share congested resources; and 3). validation of our inference methodology using bootstrap methods and nonintrusive, flow level measurements collected at a single network site. Our proposal for using flow level measurements to infer congestion sharing differs significantly from
previous research that has employed packet level measurements for making inferences. Possible applications of our method include network monitoring and root cause analysis of poor performance.



Baek, Seun-Jun and de Veciana, Gustavo "Spatial energy balancing through proactive multipath routing in wireless multihop networks" IEEE-ACM Transactions on Networking. Feb 2007, Vol. 15, Issue 1, pp 93-104.

AB In this paper, we investigate the use of proactive multipath routing to achieve energy-efficient operation of ad hoe wireless networks. The focus is on optimizing tradeoffs; between the energy cost of spreading traffic and the improved spatial balance of energy burdens. We propose
a simple scheme for multipath routing based on spatial relationships among nodes. Then, combining stochastic geometric and queueing models, we develop a continuum model for such networks, permitting an evaluation of different types of scenarios, i.e., with and without
energy replenishing and storage capabilities. We propose a parameterized family of energy balancing strategies and study the spatial distributions of energy burdens based on their associated
second-order statistics. Our analysis and simulations show the fundamental importance of the tradeoff explored in this paper, and how its optimization depends on the relative values of the energy reserves/storage, replenishing rates, and network load characteristics. For example, one of our results shows that the degree of spreading should roughly scale as the square root of the bits (.) meters load offered by a session. Simulation results confirm that proactive multipath routing decreases the probability of energy depletion by orders of magnitude versus that of a shortest path routing scheme when the initial energy reserve is high.



Kwong, D. L., Li, H. -J., Lu, N., and Peterson, J. J. "HfTiAlO dielectric as an alternative high-k gate dielectric for the next generation of complementary metal-oxide-semiconductor devices" Applied Physics Letters. Feb 19, 2007, Vol. 90, Issue 8.

AB In this letter, the authors report on the material and electrical characterizations of high dielectric constant (k) oxide HfTiAlO for the next generation of complementary metal-oxide semiconductors. Crystallization temperature has been improved to 800-900 degrees C versus that of HfO2. The substitution of Ti and Al in the HfO2 cubic structure results in an increased dielectric constant and an acceptable barrier height. The extracted dielectric constant is 36, and the band
offset relative to the Si conduction band is 1.3 eV. An equivalent oxide thickness of 11 A and low leakage have been achieved with good interfacial properties. (c) 2007 American Institute of Physics.


    Donnio, Bertrand, Sessler, Jonathan L., and Stepien, Marcin "Supramolecular liquid crystals based on cyclo[8]pyrrole" Angewandte Chemie-International Edition. 2007, Vol 46, Issue 9, pp 1431-1435.


Andersson, M., Dodabalapur, Ananth, Duran, Randolph S., Fine, Daniel,  Keizer, Henk M., and Zhu, Chenyu “Detection of single ion channel activity on a chip using tethered bilayer membranes” Langmuir.

Membrane-bound ion channels are promising biological receptors since they allow for the stochastic detection of analytes at high sensitivity. For stochastic sensing, it is necessary to measure the ion currents associated with single ion channel opening and closing events. However, this calls for stability, high reproducibility, and long
lifetimes. A critical issue to overcome is the low stability of the ion channel environment, that is, the bilayer membrane. A promising technique to surmount this is to connect the lower part of the membrane to a surface forming a tethered bilayer membrane. By reconstituting the synthetic ion channel, gramicidin A, into a tethered bilayer as part of a microchip design, we have been able to record the activity of single ion channels. The observed activity was compared with that obtained by a conventional electrophysiology method, tip dipping, to confirm its authenticity. These findings allow for the construction of stable biosensors based on ion channels and provide a novel technique for the characterization of ion channel activity.


Banerjee, Sanjay K., Kelly, David Q., Liu, Y., Mao, Chuanbin, and Tang, Shan “Protein-Mediated Nanocrystal Assembly for Flash Memory Fabrication” IEEE Transactions on Electon Devices. Mar. 2007, Vol. 54, Issue 3, pp. 433-438.

For the first time, we demonstrate that a chaperonin protein lattice can be used as a template to assemble nanocrystal (NC) arrays for Flash memory fabrication. This provides a new approach that can incorporate different types of NCs from a colloidal suspension for Flash memory fabrication. Lead selenide and cobalt NC assemblies achieved through this method have a high density of 9.5 x 10(11)/cm(2) and 1.6 x 10(12)/cm(2), respectively, as well as good distribution uniformity. Devices exhibit promising Flash memory functions, with a fiatbaiul shift of 0.5 under 8-V operation, endurance > 10(5) cycles, and retention time > 10(4) s.


Liang Wang, Daniel Fine, Deepak Sharma, Luisa Torsi and Ananth Dodabalapur. "Nanoscale organic and polymeric field-effect transistors as chemical sensors." Analytical and Bioanalytical Chemistry. Jan 2006, Vol. 384, No. 2, pp. 310-321.

This article reviews recently published work concerning improved understanding of, and advancements in, organic and polymer semiconductor vapor-phase chemical sensing. Thin-film transistor sensors ranging in size from hundreds of microns down to a few nanometers are discussed, with comparisons made of sensing responses recorded at these different channel-length scales. The vapor-sensing behavior of nanoscale organic transistors is different from that of large-scale devices, because electrical transport in a nanoscale organic thin-film transistor depends on its morphological structure and interface properties (for example injection barrier) which could be modulated by delivery of analyte. Materials used in nanoscale devices, for example nanoparticles, nanotubes, and nanowires, are also briefly summarized in an attempt to introduce other relevant nano-transducers.



Bass, J., Duine, R.A., Haney, P.M., MacDonald, A.H., Nunez, A.S., Sharma, A., Tsoi, M., and Wei, Z. “Changing exchange bias in spin valves with an electric current.” Physical Review Letters. Mar. 16, 2007, Vol. 98, Issue 11.
We show that a high-density electric current, injected from a point contact into an exchange-biased spin valve, systematically changes the exchange bias. The bias can either increase or decrease depending upon the current direction. This observation is not readily explained by the well-known spin-transfer torque effect in ferromagnetic metal circuits, but could be evidence for the recently predicted current-induced torques in antiferromagnetic metals.


Brannon-Peppas, L., Cornetta, K., Ghosn, B., and Roy, K. “Encapsulation of nucleic acids and opportunities for cancer treatment.” Pharmaceutical Research. Apr 2007, Vol. 24, Issue 4, pp. 618-627.

The development of nucleic acid drugs for the treatment of various cancers has shown great promise in recent years. However, efficient delivery of these drugs to target cells remains a significant challenge towards the successful development of such therapies. This review provides a comprehensive overview of encapsulation technologies being developed for the delivery of nucleic acid-based anti-cancer agents. Both micro and nanoparticles systems are discussed along with their use in delivering plasmid DNA as well as oligonucleotides. The majority of the systems discussed have used DNA immunotherapy as the potential mode of anticancer therapy, which requires targeting to antigen presenting cells. Other applications, including those with oligonucleotides, focus on targeting tumor cells directly. The results obtained so far show the excellent promise of encapsulation as an efficient means of delivering therapeutic nucleic acids.


Crooks, Richard M. and Ye, Heechang. “Effect of elemental composition of PtPd bimetallic nanoparticles containing an average of 180 atoms on the kinetics of the electrochemical oxygen reduction reaction” Journal of the American Chemical Society. 2007 Mar 28, Vol. 129, Issue 12, pp. 3627-3633.

PtPd bimetallic nanoparticles containing an average of 180 atoms and composed of seven different Pt:Pd ratios have been prepared within sixth-generation, hydroxyl-terminated, poly(amidoamine) dendrimers. Transmission electron microscopy indicates that the sizes of all seven nanoparticle compositions are within +/- 0.2 nm of one another and the calculated size. Single-particle energy-dispersive spectroscopy shows that the elemental composition is determined by the ratio of the Pt and Pd precursor salts used to prepare the nanoparticles. Cyclic voltammetry and rotating disk voltammetry measurements show that the Pt:Pd ratio of the nanoparticles determines their efficiency for the oxygen reduction reaction (ORR). The maximum activity for the ORR occurs at a Pt:Pd ratio of 5:1, which corresponds to a relative mass activity enhancement of 2.4 compared to otherwise identical monometallic Pt nanoparticles.


Frey, Wolfgang and Gaubert, Harold E. “Highly parallel fabrication of nanopatterned surfaces with nanoscale orthogonal biofunctionalization imprint lithography” Nanotechnology. Apr. 4, 2007 Vol. 18, Issue 13.

Large areas of nanopatterns of specific chemical functionality are needed for biological experiments and biotechnological applications. We present nanoscale orthogonal biofunctionalization imprint lithography NOBIL), a parallel top-down imprinting and lift-off technique based on step-and-flash imprint lithography (SFIL) that is able to create
centimetre-scale areas of nanopatterns of two biochemical functionalities. A photoresist precursor is polymerized with a template in place, and the thin resist layer is etched to create an undercut for lift-off. Gold nano-areas on a silicon dioxide background are then independently functionalized using self-assembly that translates the nanopattern into a cell-adhesive/cell-rejective functionality pattern. We demonstrate the technique by creating fibronectin areas down to a pattern size of 60 nm against a polyethylene glycol (PEG) background, and show initial results of cells stably seeded over an array of 1mm(2) areas of controlled size and pitch.


Freeman, Benny D., Paul, Donald R., and Rowe, Brandon W. “Effect of sorbed water and temperature on the optical properties and density of thin glassy polymer films on a silicon substrate” Macromolecules. Apr. 17, 2007, Vol. 40, Issue 8, pp. 2806-2813.

The effect of relative humidity and temperature on the refractive index and thickness of thin glassy polymer films (l similar to 500 nm) supported on silicon substrates was measured using ellipsometry. The polymers considered, polysulfone and a polyimide, exhibited increasing refractive index and film thickness with increasing relative humidity. The effect of exposure to high water activity on dry glassy polymer film properties was studied. The specific refraction, as used in the Lorentz-Lorenz equation, was determined directly for these polymers, and its dependence on temperature and aging history was examined. Water
vapor sorption in thick polymer films (l similar to 100 mu m) was measured using gravimetric techniques and shown to be consistent with the water vapor sorption measured in thin films using ellipsometry. The thin film water vapor sorption data are compared to the extreme
possibilities of volume additivity and constant volume as water is sorbed; the results fall in between these limits but closer to the constant volume case.


Liu, H.W., Zeng, Y., Landes, C. F., Kim, Y. J., Zhu, Y., Ma, X., Vo, M.N., Musier-Forsyth, K., and Barbara, P. F. “Insights on the Role of Nucleic Acid/Protein Interactions in Chaperoned Nucleic Acid Rearrangements of HIV-1 Reverse Transcription” Proceedings of the National Academy of Sciences of the United States of America Mar. 27, 2007, Vol. 104, Issue 13, pp. 5261-5267.

HIV-1 reverse transcription requires several nucleic acid rearrangement steps that are "chaperoned" by the nucleocapsid protein (NC), including minus-strand transfer, in which the DNA transactivation response element (TAR) is annealed to the complementary TAR RNA region of the viral genome. These various rearrangement processes occur in NC bound
complexes of specific RNA and DNA structures. A major barrier to the investigation of these processes in vitro has been the diversity and heterogeneity of the observed nucleic acid/protein assemblies, ranging from small complexes of only one or two nucleic acid molecules all the way up to large-scale aggregates comprised of thousands of NC and
nucleic acid molecules. Herein, we use a flow chamber approach involving rapid NC/nucleic acid mixing to substantially control aggregation for the NC chaperoned irreversible annealing kinetics of a model TAR DNA hairpin sequence to the complementary TAR RNA hairpin,
i.e., to form an extended duplex. By combining the flow chamber approach with a broad array of fluorescence single-molecule spectroscopy (SMS) tools (FRET, molecule counting, and correlation spectroscopy), we have unraveled the complex, heterogeneous kinetics
that occur during the course of annealing. The SMS results demonstrate that the TAR hairpin reactant is predominantly a single hairpin coated by multiple NCs with a dynamic secondary structure, involving equilibrium between a "Y" shaped conformation and a closed one. The
data further indicate that the nucleation of annealing occurs in an encounter complex that is formed by two hairpins with one or both of the hairpins in the "Y" conformation.


Park, K., Schougaard, S., and Goodenough, J. “Conducting-Polymer/Iron-Redox-Couple Composite Cathodes for Lithium Secondary Batteries” Advanced Materials. Mar. 19, 2007, Vol. 19, Issue 6, pp. 848.

Physically or chemically attaching an Fe-III/Fe-II redox couple to the backbone of a conducting polymer leads to stabilization of the charge/discharge characteristics and higher electrode capacities. Composite cathodes made from LiFePO4 particles bound to polypyrrole
show enhanced electrode capacities and better rate capabilities, as shown in the figure. Chemically attaching ferrocene to the pyrrole backbone not only stabilizes the charge-discharge curves but also leads to higher capacity.


Paulo Ferreira and Yang Shao-Horn.Formation Mechanism of Pt Single-Crystal Nanoparticles in Proton Exchange Membrane Fuel Cells. Electrochemical and Solid-State Letters. Jan. 17, 2007, Vol 10, Issue 3, pp. B60-B630. - Full Text

In proton exchange membrane fuel cells, hydrogen permeated from the anode to the cathode was found to reduce soluble Pt species and produce faceted and dendritic Pt nanoparticles in the cathode ionomer. Moving away from the carbon support particles, the morphology of Pt nanoparticles changed from dendritic shapes to truncated tetrahedrons, truncated octahedrons, and truncated square cuboids. Transmission electron microscopy results suggest that the homogeneity of the driving force (supersaturation) for reduction of soluble Pt at the growing surface could dictate the transition from dendritic to faceted growth, and the competition between surface energy and interfacial kinetics of Pt reduction could govern the shape of faceted Pt nanoparticles.


Arifler, D., Pavlova, I., Gillenwater, A., and Richards-Kortum, R. “Light Scattering from Collagen Fiber Networks: Micro-Optical Properties of Normal and Neoplastic Stroma.” Biophysical Journal. May 1, 2007, Vol. 92, Issue 9, pp. 3260-3274.

Development of epithelial precancer and cancer leads to well-documented molecular and structural changes in the epithelium. Recently, it has been recognized that stromal biology is also altered significantly with preinvasive disease. We used the finite-difference time-domain method, a popular technique in computational electromagnetics, to model light scattering from heterogeneous collagen fiber networks and to analyze how neoplastic changes alter stromal scattering properties. Three-dimensional optical images from the stroma of fresh normal and neoplastic oral-cavity biopsies were acquired using fluorescence confocal microscopy. These optical sections were then processed to create realistic three-dimensional collagen networks as model input. Image analysis revealed that the volume fraction of collagen fibers in the stroma decreases with precancer and cancer progression, and fibers
tend to be shorter and more disconnected in neoplastic stroma. The finite-difference time-domain modeling results showed that neoplastic fiber networks have smaller scattering cross sections compared to normal networks. Computed scattering-phase functions indicate that
high-angle scattering probabilities tend to be higher for neoplastic networks. These results provide valuable insight into the micro-optical properties of normal and neoplastic stroma. Characterization of optical signals obtained from epithelial tissues can aid in development of
optical spectroscopic and imaging techniques for noninvasive monitoring of early neoplastic changes.


Texas Researchers Aim to Use Saliva To Diagnose Health and Disease -Monday, February 12, 2007

Innovative saliva-based health diagnostic tools will be developed by John McDevitt and colleagues through a $6 million, multi-institutional grant from the National Institutes of Health.


Boul, Peter J., Cho, Dong-Gyu, Rahman, G.M.A.,  Marquez, M., Ou, Zhongping, Kadish, Karl M., Guldi, Dirk M., Sessler, Jonathan L. “Sapphyrin-Nanotube Assemblies” Journal of the American Chemical Society. May 2, 2007 Vol. 129, Issue 17, pp. 5683-5687.

Single wall carbon nanotubes (SWNTs) bind strongly to sapphyrins, quintessential pentapyrrolic "expanded porphyrin" macrocycles, through donor-acceptor stacking interactions. The specific use of a functionalized sapphyrin diol yields stable water-suspendable nanotubes and also permits the formation of well-defined assemblies in ionic liquids. The absorption and steady-state fluorescence spectra of the resulting noncovalently functionalized nanotube complexes have been analyzed in aqueous media and ionic liquids, yielding a description of the photophysical properties of the nanotube-sapphyrin complexes as nor-acceptor species for light-harvesting.


Nadkarni, Suvid and Dodabalapur, Ananth “Organic Transistor Based Circuit as Drive for Planar Microfluidic Devices” Journal of Materials Science-Materials in Electronics. Sep. 2007. Vol. 18, Issue 9, pp 931-937.

Organic transistor based circuits are a promising candidate for acting as drivers for microfluidic devices handling discrete droplets. The ease of fabrication along with the ability to generate desired voltage levels for performing electrowetting based actuation of liquids make them an ideal match for discrete droplet based microfluidic systems. In this article, we report the implementation of an organic transistor based complementary metal-oxide semiconductor (CMOS) inverter used to actuate microliter quantities of droplets on a simple planar microfluidic device. We also present two approaches for fabricating an open-structured device for different applications. The inverter is fabricated using Pentacene and N, N'- bis (n-octyl) dicyanoperylene-3, 4:9, 10-bis (dicarboxyimide) (PDI-8CN(2)) (Northwestern University).  The inverter output is stable and repeatable and is used to actuate droplets over adjacent electrodes as well as in merging of discrete droplets.

Top 2 Hottest Paper in Acta Materialia

Prof. Paulo Ferreira and Ph.D student Chris Carlton’s recently published paper in Acta Materialia entitled “What is behind the Inverse Hall-Petch Effect in Nanocrystalline Materials?” is attracting a wide attention from the scientific community. The paper shows that the Hall-Petch equation developed in the 50’s
is just a particular case of a more general phenomenon, where the inverse Hall-Petch effect in nanomaterials can be predicted.


Hot New Paper from CNM Fellow Zhen Yao - "Room-Temperature Single-Electron Transistors Using Alkanedithiols" - pdf

Published in the November 2007 issue of IOP Publishing journal Nanotechnology



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