GGPF 25th Anniversary Symposium & Banquet: From Macro to Nano
October 23 & 24, 2005
Embassy Suites, Burlingame, CA
R. Bruce Prime and Martha M. Steiner, Symposium Co-Chairs
The Golden Gate Polymer Forum traces its roots to a symposium held in June 1980, at which attendees enthusiastically endorsed the formation of a local group with a primary focus on polymer characterization. GGPF has evolved over the years and now addresses a broad scope of polymer issues. Over the same time period the size scale of many features and even devices has shrunk from micrometers to nanometers, providing the theme for this symposium. GGPF celebrates 25 years of serving the educational and networking needs of Bay Area scientists and engineers with this two-day symposium and banquet.
Four technical sessions will be held, in the mornings and afternoons of each day. The first day will conclude with a banquet and a brief history of GGPF where contributors over the 25 years will be recognized. The schedule follows. Available speaker abstracts and biographical sketches are given below.
The symposium will be held at the Embassy Suites, 150 Anza Boulevard, Burlingame, CA 94010, 650/342-4600, www.embassyburlingame.com. The hotel is located on the San Francisco Bay a short distance from the San Francisco Airport. Complementary 24-hour shuttle service is available from the airport every 15 minutes from the ARRIVALS level.
Directions from San Jose: 101 North, exit Anza Boulevard.
Directions from San Francisco: 101 South, exit Burlingame/Broadway, follow sign to 101 overpass, turn right on Old Bayshore, left on Airport Boulevard, left on Anza Boulevard.
There is ample free parking at the hotel.
Sunday October 23
7:30 am Registration opens
8:00 am Continental Breakfast
8:30 am Bruce Prime, Introductory Remarks
Session A: Polymers in Energy & the Environment
Chair: John Kerr, Lawrence Berkeley National Laboratory
8:40 am Steve Hamrock, 3M, “The Development of New PEM (Proton Exchange Membrane) Fuel Cell Membranes at 3M”
9:30 am Nitash Balsara, UC Berkeley, “Ion-Containing Block Copolymer Nanostructures”
10:20 am Break
10:50 am Tim Merkel, Membrane Technology Research, “Gas Separation Membranes: Current Status and Future Trends”
11:40 am Jim Sheats, Nanosolar, "Applications of Polymers in Photovoltaics"
12:30 pm Lunch
Session B: Patterning with Polymers I, from Macro to Micro
Chair: April Baugher, Applied Biosystems
1:30 pm Sue Carter, UC Santa Cruz, “Screen-printing Methods for Patterning Low Cost Fully Printed Polymer-based Light Emitting Displays”
2:15 pm Michael Chabinyc, PARC, “On the Road to Plastic Electronics: Patterning Semiconducting Polymers for Displays”
3:00 pm Break
3:30 pm Arthur L. Chait , EoPlex Technologies, Inc., “High-Volume Print Forming, HVPFÔ; Using Polymer Systems To Manufacture Large Volumes Of Complex Polymer, Metal-Ceramic and Hybrid Components”
4:15 pm Nick Sheridan, Gyricon, "The Gyricon- A MEMS Polymer Display"
5:00 pm Session ends, free time
6:00 pm Wine and Cheese Reception
7:00 pm Banquet, Historical Retrospective of GGPF
Monday October 24
8:00 am Registration opens, Continental Breakfast
Session C: Patterning with Polymers II, from Micro to Nano
Chair: Clayton Henderson, Hitachi Global Storage Systems
8:30 am Grant Willson, University of Texas, “Dual Damascene by Imprint Patterning of Dielectric Materials”
9:15 am William P. King, Georgia Institute of Technology, “Nanomanufacturing in Novel Materials using Thermal Processing”
10:00 am Break
10:15 am Blake A. Simmons, Sandia National Laboratories, “Design, Fabrication, and Evaluation of Polymeric Microfluidic Devices for the Monitoring and Separation of Water-Borne Pathogens”
11:00 am Ronald Jones, NIST, “Fidelity and Stability in Nanoscale Polymer Patterning”
11:45 am Jennifer Lu, Agilent Technologies, “Producing Active Inorganic Nanostructures via Solution and Thin Film Self-assembly of Block Copolymers”
12:30 pm Lunch
Session D: Biopolymer Materials & Devices
Chair: Lothar Kleiner, Guidant Corporation
1:30 pm Allan Hoffman, University of Washington, “A Perspective on Polymers in Medicine”
2:10 pm Stuart Williams, University of Arizona, “Biomaterial-Directed Tissue Responses: Material Design and Modification”
3:10 pm Break
3:40 pm Subbu Venkatraman, Nanyang Technical University, Singapore, "Biodegradable Polymers: Selected Medical Applications"
4:30 pm Fuh-Wei Tang, Guidant, “Micro and Nano-scale Characterization of Biomaterials and Devices”
5:20 pm Session and Symposium ends
For course content questions contact Bruce Prime, firstname.lastname@example.org
For registration questions, contact Martha M. Steiner, email@example.com
For GGPF web page issues, contact GGPF Webmaster Russ Beste, firstname.lastname@example.org
If you can't reach any of the above, contact Clayton Henderson, Clayton.Henderson@HitachiGST.com
***************** Speaker Abstracts *****************
Session A (Sunday Morning): Polymers in Energy & the Environment
Chair: John Kerr, Lawrence Berkeley National Laboratory
The Development of New PEM Fuel Cell Membranes at 3M*
Steven Hamrock, 3M Fuel Cell Components Program,
3M Center, Building 201-1W-28, St. Paul, MN 55144
Over the last 20 years there has been a significant increase in research and development in the area of proton exchange membrane fuel cells (PEMFC’s), as well as a significant increase in investment in this technology, from both the public and private sector. This increase has arisen in part due to the increased world wide demand for energy, as well as the increase in its cost. Concerns about the limited supply and environmental impact of fossil fuels also play a role in the growing interest in these systems. Many see PEMFC’s as a central technology to the realization of a “hydrogen economy” based on hydrogen derived from renewable resources such as wind and solar energy. Development and commercialization of affordable hydrogen fuel cells are necessary for the realization of such a hydrogen-based economy. While many breakthroughs have been made over the last ten years in the area of PEMFC’s, technical and economic barriers for their commercialization still exist.
*This research was supported in part by the U.S. Department of Energy, Cooperative Agreement No. DE-FC36-02AL67621. DOE support does not constitute an endorsement by DOE of the views expressed in this presentation.
Polymer LEDs in Solid State Lighting
Homer Antoniades, Osram Optosemiconductor
Block Copolymers as Electrolytes for Lithium Polymer Batteries
Nitash Balsara , UC Berkeley
Gas Separation Membranes: Current Status and Future Trends
Tim Merkel, Membrane Technology Research
In the past 20 years, polymer membrane-based gas separations have become an established unit operation. This presentation will discuss the developments that led to commercial gas separation membranes, polymer structure-property relationships used for materials selection guidelines, and promising new membrane gas separation applications. To expand into new petrochemical and refinery areas, membranes must be able to withstand harsh chemical and thermal environments. Robust materials that can maintain separation performance through repeated system upsets over long periods of time are desired. Ongoing research at MTR is directed toward the development of novel nanocomposite and plasticization-resistant membranes. These “next-generation” membrane materials, and the rationale behind them, will be discussed.
Applications of Polymers in Photovoltaics
Jim Sheats, Nanosolar
Session B (Sunday Afternoon): Patterning with Polymers I, from Macro to Micro
Chair: April Baugher, Applied Biosystems, 850 Lincoln Centre Drive, Foster City 94404
Screen-printing Methods for Patterning Low Cost Fully Printed Polymer-based Light Emitting Displays
Sue A. Carter, Chief Technical Advisor, Add-vision, Inc., Scotts Valley
Physics Department, University of California, Santa Cruz
Large potential markets exist for polymer-based organic light emitting displays (OLED) in temporary or low duty-cycle applications if the OLED display can be made at sufficiently low cost. Fully printed OLED displays made by screen-printing and related manufacturing technologies offer the ability to meet these costs because of the low cost of capital equipment and the use of low skilled labor. However, several challenges exist in producing such OLED displays, not the least of which is producing efficient devices on plastic substrates with printed cathodes. In this presentation, I will discuss the process and materials that Add-vision has developed to make large area fully printed light emitting polymer (LEP) displays on flexible plastic substrates using a screen printing process under ambient, non clean-room, conditions. I will discuss several or the challenges we have faced in our development process and the solutions we have employed to overcome many of these challenges. These solutions include the development of a PIN architecture to enable the use of a printable air stable Ag-based cathode for efficient electron injection in addition to the ability to use a relatively thick active LEP layer that mitigates substrate and print nonuniformities, particle contamination and shorting. I will describe our most recent results on display performance, our manufacturing and encapsulation process, and the path forward to full manufacturing and commercialization. I will conclude by showing OLED displays on plastic substrates that we fully patterned using low cost screen printing and by discussing potential markets for these displays, including markets where 100 hours of "on-time" life is sufficient when reasonable shelf-life and low costs can be realized.
web sites: www.add-vision.com, www.physics.ucsc.edu/~sacarter
On the Road to Polymer Electronics: Patterning Semiconducting Polymers for Displays
Michael L. Chabinyc, PARC: Palo Alto Research Center, Palo Alto, CA
Organic materials are forming a new basis for the manufacture of electronic devices, such as displays, and they will be used increasingly as both substrates and active materials. The electrical performance of thin-film transistors, TFTs, formed with semiconducting polymers is rapidly approaching that of amorphous silicon. Processing methods are critical for the achievement of high electrical performance in practical applications. In polymeric TFTs, electrical conduction occurs within a few molecular layers (~5% of the total film thickness) of the semiconducting polymer at the interface with the gate dielectric; the process of formation of this interfacial layer can have a profound impact on electrical performance of TFTs. A number of novel patterning methods that can be used to form high performance TFTs will be described including inkjet printing and microfluidic patterning. Issues related to electrical stability of polymeric TFTs will also be discussed.
High-Volume Print Forming, HVPFä; Using Polymer Systems To Manufacture Large Volumes Of Complex Polymer, Metal-Ceramic and Hybrid Components
Arthur L. Chait, EoPlex Technologies, Inc., Redwood City, CA
The company’s proprietary print-forming technology can produce large volumes of three-dimensional structures from a wide range of materials. The EoPlex process is called High Volume Print-Forming™ (HVPF™) and it allows for thousands of small, complex structures to be built simultaneously. Parts are designed in layers and customized printing machines are used to deposit special “polymer inks” which carry ceramic, metallic or polymer materials to millions of locations. Materials are then cured, fused, sintered, cofired or bonded together in post processing steps.
With the EoPlex process complex shapes such as three-dimensional grids, interwoven circuits, assemblies with multiple parts, and multiple materials can be produced at the same time. The process also makes it cost effective to mass-produce products which would be difficult or impossible to manufacture using conventional techniques. Virtually any shape can be produced including complex components with cavities, chambers and even moving parts. The greatest cost advantage is with miniature structures but larger sizes are also possible. Identified market applications include: electronic packaging, passive electronic components, RF and microwave components, medical devices, unique 3-D circuits, fuel cells, batteries, mechanical components, switches, connectors and sensors.
The presentation will focus on the basic technology, manufacturing and materials that make the EoPlex processes possible; the new design rules that are enabled and how this translates to advantages for customers.
EoPlex Technologies is a Redwood City, CA company that is commercializing a family of new technologies to manufacture miniature electronic components and subassemblies. The company is backed by Draper Fischer Jurvetson, Labrador Ventures, and Draper-Richards.
The Gyricon - A MEMS Polymer Display
Nick Sheridon, Gyricon LLC, Palo Alto, CA
The Gyricon is an Electronic Paper display consisting of 100micron diameter polyethylene balls dispersed in a silicone elastomer sheet. Each ball is pigmented to have hemispheres of contrasting colors. The hemispheres have different permanent charges associated with them, so the balls possess a dipole moment, causing them to orient in an external electrical field. Unique processes are employed to fabricate the balls and to disperse them within individual oil filled cavities in the silicone elastomer sheet. Gyricon LLC is manufacturing low power wireless electronic signs based on this technology.
Session C (Monday Morning): Patterning with Polymers II, from Micro to Nano
Chair: Clayton Henderson, Hitachi Global Storage Systems
"Dual Damascene by Imprint Patterning of Dielectric Materials"
Grant Willson, University of Texas, http://willson.cm.utexas.edu/
The “Back End of Line” (BEOL) electrical connectivity in a modern integrated circuit (IC) may contain as many as ten levels of wiring and associated vias. The dual damascene process used to generate these copper interconnects requires many difficult processing steps. BEOL processing using Step and Flash Imprint Lithography (SFIL) with a directly patternable dielectric material can dramatically reduce the number of processing steps. A single SFIL imprint can simultaneously generate both the via and the trench with a single alignment and lithography step. By directly patterning a dielectric material instead of a sacrificial resist material, many hardmasking materials and pattern transfer processes are eliminated. This paper describes progress on integration of this process into the Sematech wafer process flow and the characterization of new, Directly Patternable Dielectrics (DPD’s). The fabrication of multilevel templates will be described together with successful processing of eight inch wafers through the full process sequence at SEMATECH including first electrical test data. The key to success in this endeavour is the design of the image
ble dielectric material, which must meet a number of demanding functional requirements. Progress in the design of these materials will also be presented. If this process can be fully implemented, it would offer a huge cost saving and accelerate the implementation of imprint lithography in semiconductor manufacturing.
The first materials used in our experiments do not meet the thermal stability requirements. However, there are several potential routes to a photocurable dielectric material. One promising route is based on variations of hydridosilsesquioxane (HSQ) type materials. HSQ-type materials already find use as “spin on glass” dielectric materials in semiconductor manufacturing. As polymers, HSQ materials are too viscous for SFIL processing, but imprinting precursors and generating polymers in situ during the imprint step provides a way around this problem. A first functionalized HSQ cage structure has been imprinted as a demonstration. The cage was “dual functionalized” with two different reactive groups. Appending acrylate functional groups on to the cage structure allowed printing through curing by free radical initiated polymerization. Appending groups, such as maleimides and benzocyclobutane that cure thermally with minimal shrinkage gives a path to a final, thermal cure that provides improved mechanical properties. The initial photo curing step is fast which allows imprint tool throughput. The post imprint bake step fully hardens the material giving improved mechanical and thermal stability. The thermal cure process is compatible with the incorporation of a porogen, which provides a straightforward route to a imprintable porous low-k dielectric material.
Nanomanufacturing in Novel Materials using Thermal Processing
William P. King, Georgia Institute of Technology
This talk describes research on thermal processing at length scales from 10 nm - 50 um, with applications in manufacturing, surface analysis, electronics cooling, energy management, and data storage. The research includes development of microelectromechanical systems (MEMS)-based tools for instrumentation and manufacturing. In one research thrust, silicon micromachined atomic force microscope (AFM) cantilevers have been fabricated with integrated heaters. When the nanometer-scale cantilever tip is in contact with a surface, the area of contact is the smallest controlled heat source ever produced. As such it can be used for data storage, surface analysis, and novel nanofabrication processes. I will describe the engineering of these cantilevers, their use as a nanometer-scale soldering iron, and their use to characterize micron-scale liquid flows. In another research thrust, three-dimensional nanostructured surfaces are used in a hot embossing forming process, where features as small as 10 nm can be replicated in thermoplastic substrates. This technique has been used to manufacture micrometer scale and nanometer scale features in biomaterials for use as tissue scaffolds. Simulations of polymer flow at these small length scales aid in the rational design of the manufacture of these substrates.
Design, Fabrication, and Evaluation of Polymeric Microfluidic Devices for the Monitoring and Separation of Water-Borne Pathogens
Blake A. Simmons, Sandia National Laboratories, Livermore, CA USA 94551-0969
We have successfully demonstrated the selective trapping, concentration, and release of various biological organisms and inert beads by utilizing a phenomenon known as insulator-based dielectrophoresis (iDEP) within a polymeric microfluidic device. The microfluidic channels and internal features, in this case arrays of insulating posts, were initially created through standard wet-etch techniques in glass. This glass chip was then transformed into a nickel stamp through electroplating. The resultant nickel stamp was then used as the replication tool to produce the polymeric devices through injection molding. The polymeric devices were made of Zeonor® 1060R, a polyolefin copolymer thermoplastic selected for its superior chemical resistance and optical properties. These devices were then optically aligned with another polymeric substrate that had been machined to form fluidic vias. The sealed devices were utilized to selectively separate and concentrate a variety of biological pathogen simulants and organisms. These organisms include bacteria and spores that were selectively concentrated and released by simply applying D.C. voltages across the polymer channels via platinum electrodes located off-chip at the inlet and outlet reservoirs. The dielectrophoretic response of the organisms is observed to be a function of the applied electric field as well as post size, geometry and spacing. Cells were selectively trapped against a background of labeled polystyrene beads and spores to demonstrate that samples of interest can be separated from a diverse background. We have implemented a methodology to determine the concentration factors obtained in these devices, and have also investigated the impact of surface coatings (dynamic and static) on device performance.
Fidelity and Stability in Nanoscale Polymer Patterning
Ronald Jones, NIST
A common challenge to all forms of nanofabrication is the capability to accurately and precisely measure the size, shape, and homogeneity of the resulting nanostructures or nanostructured materials. In addition to single layer devices, many applications will require multiple levels of assembly producing 3-D arrays of nanostructures. We have developed a technique based on X-ray scattering, termed Critical Dimension Small Angle X-ray Scattering (CD-SAXS) capable of 3-dimensional non-destructive measurements of structural dimensions ranging from 5 to 500 nm in size with sub-nm precision. We will illustrate the capabilities of this technique for nanofabrication using data from recent studies comparing the dependence of imprint shape and size on imprint temperature and polymer composition. The fidelity of pattern transfer is then established through comparison to the dimensions of the mold using the same measurement procedure. The stability of the resulting structures is then evaluated through in-situ measurements of the rate of shape evolution in nanostructures annealed above the glass transition temperature. CD-SAXS data demonstrate a reduction in stability of thermally embossed homopolymers with increasing molecular weight, suggesting an important design challenge for devices based on functional polymer nanostructures.
Producing Active Inorganic Nanostructures via Solution and Thin Film Self-assembly of Block Copolymers
Jennifer Lu, Agilent Technologies
Block copolymers, a class of self-assembling macromolecules, can be spontaneously self-organized into well-ordered morphologies on the nanometer scale. Metal-containing block copolymers offer great promise for producing various active nanostructures. In this talk, I will describe using block copolymer templates to generate ordered transition metal nanostructures and nanotextured surfaces via solution or thin film self-assembly. Co, Fe, Ni, and Au nanostructures with controlled size and periodicity have been successfully produced. These catalytically active nanostructures promote the controllable synthesis of carbon nanotubes and nanowires. Nanotubes and nanowires with small diameter, narrow size distribution and uniform densities over a large surface area have been successfully produced. By combining the self-assembly technique with top-down photolithography, selective growth of CNTs on a surface or in suspension has been achieved. We have also demonstrated the feasibility of lithographically selective growth of Si nanowires on a 3 inch wafer. Au and Ag nanodots and Au and Ag nanotextured surfaces have also been fabricated using nano-templates formed by block copolymers. The nanotextured surfaces exhibit different surface plasmon resonance behavior than untextured surfaces, suggesting possible applications in SERS or SPR based molecular detection.
Session D (Monday Afternoon): Biopolymer Materials & Devices
Chair: Lothar Kleiner, Guidant Corporation
A Perspective on Polymers in Medicine
Allan Hoffman, University of Washington
In this talk I will give a personal perspective on the evolution of polymers in medical implants and devices over the past 50 years. My major critical focus will be on current important areas of research and development. I will begin with an introduction highlighting the pioneers in this field from the earliest days to the present. I will follow with consideration of the following topics:
· Polymer-drug conjugates and complexes
· PEG and its use as a component of drug delivery formulations
· Tissue engineering and important issues of scaffold design, including porosity, the use of RGD and similar cell receptor ligands, and drug delivery to and within scaffolds
Allan S. Hoffman studied at M.I.T., where he received B.S., M.S., and Sc.D. degrees in Chemical Engineering between 1953 and 1957. He taught on the faculty of M.I.T. Chemical Engineering Department for a total of ten years. He also spent four years in industry. Since 1970 he has been Professor of Bioengineering at the University of Washington in Seattle, Washington.
Biomaterial-Directed Tissue Responses: Material Design and Modification
Stuart Williams, University of Arizona
The implantation of medical devices results in a tissue response that is most often characterized as the formation of a relatively avascular fibrous capsule. The formation of this capsule is often associated with device failure and, for this reason; new biomaterials have been designed and evaluated to alter biomaterial associated tissue responses. Numerous material characteristics have been considered and evaluated including base polymer chemistry, material porosity and more recently surface modification of biomaterials. The result of these studies is a new generation of biomaterials that can direct tissue responses. One such response is the formation of functional blood vessels in association with implants as well as the reduction in the formation of a fibrous capsule. These modifications are equally important toward improved function of intravascular devices such as stents.
Biodegradable Polymers: Selected Medical Applications
Subbu Venkatraman, Nanyang Technical University, Singapore
We survey the field of biodegradable polymers, as used in medical applications. Although research in this field has been prolific, it has not translated into commercialized devices. We focus on two areas where such polymers would bring substantial benefits: stents and drug carriers. Urological, bronchial, peripheral vascular and coronary stents will be reviewed. I will present some of our work on bioabsorbable self-expanding stents, and focus on controlled release from multilayered stents. Multilayerd stents offer some interesting options for degradation and for controlled release. Finally, animal studies on our urological stent will be discussed in terms of histo-compatibility and in vivo degradation.
The drug carrier work involves the use of block copolymers of PLA with PEG. We will present the characterization of such polymers, and their usefulness as “stealth” carriers for chemotherapeutics.
Micro and Nano-scale Characterization of Biomaterials and Devices
Fuh-Wei Tang, Guidant
The release mechanism of a drug controlled release device is a function of the materials used and the coating nature of the drug carrier. Understanding the fundamental properties of the polymeric materials and their coating nature plays an important role in understanding and interpreting the release mechanism. The micro and nano-scale characterization of material properties such as sequence of the copolymer, crystal conformation difference, formation and stability of different morphologies, and drug /polymer interference etc. provides important information to understand the release mechanism of a polymeric material based drug controlled release device.
Knowledge of the coating nature such as lateral and depth coating uniformity, swelling behavior etc. is also important to understand the performance of the drug controlled release device. For example, characterization of swelling properties of the polymer coatings after being immersed in relevant environments provides information to understand and control (1) the integrity and durability of the coating, (2) drug release behavior, and (3) potential bulk biological interaction of polymer with tissues.
Micro and nano-scale characterization tools for material and device such as Nuclear Magnetic Resonance (NMR), Electron Spin Resonance (ESR). Laser Con-focal Raman (LCR), Focal Planar Imaging FTIR, Atomic Force Microscopy (AFM), and Micro Thermal Analysis etc. are powerful techniques for characterization of materials and devices for drug controlled release. The use of these tools for micro and nano-scale characterization in the design of drug controlled release devices shall be addressed and discussed.